Sample records for electron edm search from WorldWideScience.org

Searches for permanent electric dipole moments (EDM) of fundamental particles have been underway for more than 50 years with null results. Still, such searches are of great interest because EDMs arise from radiative corrections involving processes that violate parity and time-reversal symmetries, and through the CPT theorem, are sensitive to CP-violation. New models of physics beyond the standard model predict new sources of CP-violation leading to dramatically enhanced EDMs possibly within the reach of a new generation of experiments. We describe a new approach to electronEDMsearches using molecular ions stored in a tabletop electrostatic storage ring. Molecular ions with long-lived paramagnetic states such as tungsten nitride WN+ can be injected and stored in larger numbers and with longer coherence times than competing experiments, leading to high sensitivity to an electronEDM. Systematic effects mimicking an EDM such as those due to motional magnetic fields and geometric phases are found not to limit the approach in the short term, and sensitivities of ?|de| ? 10-30 e·cm/day appear possible under conservative conditions.

Searches for permanent electric dipole moments (EDM) of fundamental particles have been underway for more than 50 years with null results. Still, such searches are of great interest because EDMs arise from radiative corrections involving processes that violate parity and time-reversal symmetries, and through the CPT theorem, are sensitive to CP-violation. New models of physics beyond the standard model predict new sources of CP-violation leading to dramatically enhanced EDMs possibly within the reach of a new generation of experiments. We describe a new approach to electronEDMsearches using molecular ions stored in a tabletop electrostatic storage ring. Molecular ions with long-lived paramagnetic states such as tungsten nitride WN+ can be injected and stored in larger numbers and with longer coherence times than competing experiments, leading to high sensitivity to an electronEDM. Systematic effects mimicking an EDM such as those due to motional magnetic fields and geometric phases are found not to limit the approach in the short term, and sensitivities of ?|de| ? 10-30 e·cm/day appear possible under conservative conditions.

Trapped molecular ions provide large effective electric fields and long electron spin coherence times for the search for an electron electric dipole moment (eEDM). In particular, the ^3?1 state of HfF^+ has been proposed as a candidate for the eEDMsearch. To create HfF^+, we optically excite a supersonic beam of neutral HfF with two photons to an autoionizing state, and then perform laser-induced fluorescence to detect the state of the resultant HfF^+ ions. We report on our efforts to understand the autoionization process for efficient state preparation of HfF^+ ions, and on our general progress towards an eEDM measurement. This work is funded by the US National Science Foundation.

The discovery of a permanent electric dipole moment (EDM) of a fundamental particle would prove a great discovery in modern physics; such an EDM would violate two or three of the core symmetries of the fundamental forces of nature. Many models that go beyond the standard model of particle physics produce EDMs with magnitudes approaching the level detectable by the next generation of experiments. One possibility for such an experiment involves the use of a solid sample at low temperatures. In a paramagnetic material, the unpaired electrons, if they possess an EDM, can interact with the polarization of the sample and produce a magnetization that can be detected. This dissertation discusses an incarnation of such an experiment based on mixed europium-barium titanates. Such an experiment offers several advantages over other solid-state and atomic EDMsearches including larger electronEDM induced interactions and the ability to measure without an applied electric field. This experiment has produced the world's best limit on the electronEDM to date from a solid sample, at |de| < 6.05 × 10-25 ecm (90% confidence limit). While this limit represents an improvement in the realm of solid-state experiments, it is not yet competitive with similar molecular and atomic experiments. However, there are many possibilities that could produce a superior solid-state experiment, and these will be discussed.

Full Text Available Measurement of a non-zero electric dipole moment (EDM of the electron within a few orders of magnitude of the current best limit of |de| < 1.05 × 10?27?e?cm [1] would be an indication of physics beyond the Standard Model. The ACME Collaboration is searching for an electronEDM by performing a precision measurement of electron spin precession in the metastable H3?1 state of thorium monoxide (ThO using a slow, cryogenic beam. We discuss the current status of the experiment. Based on a data set acquired from 14 hours of running time over a period of 2 days, we have achieved a 1-sigma statistical uncertainty of ?de = 1 × 10?28?e?cm/?T, where T is the running time in days.

Measurement of a non-zero electric dipole moment (EDM) of the electron within a few orders of magnitude of the current best limit of |d_e| < 1.05 e -27 e cm would be an indication of physics beyond the Standard Model. The ACME Collaboration is searching for an electronEDM by performing a precision measurement of electron spin precession in the metastable H state of thorium monoxide (ThO) using a slow, cryogenic beam. We discuss the current status of the experiment. Based on a data set acquired from 14 hours of running time over a period of 2 days, we have achieved a 1-sigma statistical uncertainty of 1 e -28 e cm/T^(1/2), where T is the running time in days.

All current experiments searching for an electronEDM d_e are performed with atoms and diatomic molecules. Motivated by significant recent progress in searches for an EDM-type signal in diatomic molecules with an uncompensated electron spin, we provide an estimate for the expected signal in the Standard Model due to the CKM phase. We find that the main contribution originates from the effective electron-nucleon operator $\\bar{e} i\\gamma_5 e \\bar{N}N$, induced by a combination of weak and electromagnetic interactions at $O(G_F^2\\alpha^2)$, and not by the CKM-induced electronEDM itself. When the resulting atomic P,T-odd mixing is interpreted as an {\\it equivalent} electronEDM, this estimate leads to the benchmark $d_e^{equiv}(CKM) \\sim 10^{-38}$ ecm.

The existence of a non-zero electric dipole moment (EDM) implies the violation of time reversal symmetry. As the time-reversal symmetry violation predicted by the Standard Model (SM) for the electronEDM is too small to be observed with current experimental techniques and any a non-zero EDM would indicate new physics beyond the SM. The tiny signal from the electronEDM is enhanced in the heavy atoms such as francium (Fr). We are constructing the laser-cooled Fr factory to search for the electronEDM.

Full Text Available The search for the electric-dipole moment (EDM of laser-cooled francium (Fr atoms could lead to a measurement for the electronEDM. It is predicted that the electronEDM would be enhanced by approximately three orders of magnitude in heavy atoms such as Fr. Laser-cooling and trapping techniques are expected to suppress statistical and systematic errors in precision measurements. The magneto-optical trap was achieved using stable rubidium in a developing factory of laser-cooled radioactive atoms. In light of the results from the rubidium experiments, we found that an upgrade of each apparatus is preferred for Fr trapping.

Molecules can be advantageous for the search for the electron electric dipole moment (eEDM) due to the large effective electric field experienced by a bound, unpaired electron. Furthermore, the closely-spaced states of opposite parity make the molecules easy to polarize in the lab frame. The JILA eEDM experiment currently uses HfF^+ molecules in an ion trap to achieve long coherence times to reduce systematics. When an electric field is applied the eEDM signal is proportional to the shift in energy splitting between two Zeeman levels in a low-lying, metastable ^3?_1 state. We have previously shown efficient preparation of trapped HfF^+ molecules in the rovibronic ground state, X^1?^+(v=0,J=0). Here, we demonstrate coherent transfer of population from the ground state to the a^3?_1(v=0, J=1) state through an intermediate ^3?_{0+} state and efficient state read-out using photodissociation. In addition, we have begun to take spectroscopy data of the hyperfine and Zeeman structure of the eEDM science state in the presence of a rotating bias electric field and a magnetic field. A. E. Leanhardt et. al., Journal of Molecular Spectroscopy 270, 1-25 (2011). H. Loh et. al., Journal of Chemical Physics 135, 154308 (2011).

We report ab initio relativistic correlation calculations of potential curves and spectroscopic constants for four lowest-lying electronic states of the lead monofluoride. We also calculated parameters of the spin-rotational Hamiltonian for the ground and the first excited states including P,T-odd and P-odd terms. In particular, we have obtained hyperfine constants of the $^{207}$Pb nucleus. For the $^2\\Pi_{1/2}$ state $A_\\perp=-6859.6$ MHz, $A_\\|=9726.9$ MHz and for the A$^2\\Sigma^+_{1/2}$ $A_\\perp=1720.8$ MHz, $A_\\|=3073.3$ MHz. Our values of the ground state hyperfine constants are in good agreement with the previous theoretical studies. We discuss and explain seeming disagreement in the sign of the constant $A_\\perp$ with the recent experimental data. The effective electric field on the electron $E_{eff}$, which is important for the planned experiment to search for the electric dipole moment of the electron, is found to be 3.3 * 10^{10} V/cm.

The importance of initiating new search techniques for neutron EDM is emphasised in this short paper. Crystal techniques allow to investigate the interaction of neutrons with electric fields of the order of several 109 V cm sup - sup 1. This gives the possibility to test CP- and T-violations at stronger electric field levels than ever before.

The current limit on the electron's electric dipole moment, $|d_\\mathrm{e}|<8.7\\times 10^{-29} e {\\cdotp} {\\rm cm}$ (90% confidence), was set using the molecule thorium monoxide (ThO) in the $J=1$ rotational level of its $H ^3\\Delta_1$ electronic state [Science $\\bf 343$, 269 (2014)]. This state in ThO is very robust against systematic errors related to magnetic fields or geometric phases, due in part to its $\\Omega$-doublet structure. These systematics can be further suppressed by operating the experiment under conditions where the $g$-factor difference between the $\\Omega$-doublets is minimized. We consider the $g$-factors of the ThO $H^3\\Delta_1$ state both experimentally and theoretically, including dependence on $\\Omega$-doublets, rotational level, and external electric field. The calculated and measured values are in good agreement. We find that the $g$-factor difference between $\\Omega$-doublets is smaller in $J=2$ than in $J=1$, and reaches zero at an experimentally accessible electric field. This ...

An Electric Dipole Moment (EDM) of the elementary particle is a good prove to observe the phenomena beyond the Standard Model. A non-zero EDM shows the violation of the time reversal symmetry, and under the CPT invariance it means the CP violation. In paramagnetic atoms, an electronEDM results in an atomic EDM enhanced by the factor of the 3rd power of the charge of the nucleus due the relativistic effects. A heaviest alkali element francium (Fr), which is the radioactive atom, has the largest enhancement factor K ~ 895. Then, we are developing a high intensity laser cooled Fr factory at Cyclotron and Radioisotope Center (CYRIC), Tohoku University to perform the search for the EDM of Fr with the accuracy of 10-29 e · cm. The important points to overcome the current accuracy limit of the EDM are to realize the high intensity Fr source and to reduce the systematic error due to the motional magnetic field and inhomogeneous applied field. To reduce the dominant component of the systematic errors mentioned above, we will confine the Fr atoms in the small region with the Magneto-Optical Trap and optical lattice using the laser cooling and trapping techniques. The construction of the experimental apparatus is making progress, and the new thermal ionizer already produces the Fr of ~106 ions/s with the primary beam intensity 200 nA. The developments of the laser system and optical equipments are in progress, and the present status and future plan of the experimental project is reported.

An Electric Dipole Moment (EDM) of the elementary particle is a good prove to observe the phenomena beyond the Standard Model. A non-zero EDM shows the violation of the time reversal symmetry, and under the CPT invariance it means the CP violation. In paramagnetic atoms, an electronEDM results in an atomic EDM enhanced by the factor of the 3rd power of the charge of the nucleus due the relativistic effects. A heaviest alkali element francium (Fr), which is the radioactive atom, has the largest enhancement factor K ? 895. Then, we are developing a high intensity laser cooled Fr factory at Cyclotron and Radioisotope Center (CYRIC), Tohoku University to perform the search for the EDM of Fr with the accuracy of 10-29 e · cm. The important points to overcome the current accuracy limit of the EDM are to realize the high intensity Fr source and to reduce the systematic error due to the motional magnetic field and inhomogeneous applied field. To reduce the dominant component of the systematic errors mentioned above, we will confine the Fr atoms in the small region with the Magneto-Optical Trap and optical lattice using the laser cooling and trapping techniques. The construction of the experimental apparatus is making progress, and the new thermal ionizer already produces the Fr of ?106 ions/s with the primary beam intensity 200 nA. The developments of the laser system and optical equipments are in progress, and the present status and future plan of the experimental project is reported.

Observation of an electric dipole moment (EDM) of the electron would imply CP violation beyond the Standard Model. This experiment searches for the electronEDM using a metastable state of the PbO molecule. Several unique properties of this state, including closely spaced levels of opposite parity and a long coherence time, make it suitable for use in a vapor cell, which in turn enables high counting rates. The closely spaced levels of opposite parity are due to omega-doubling. Roughly speaking this doubling leads to states with oppositely directed internal electric fields but otherwise nearly identical properties. This reversal along with those of the lab electric and magnetic fields allow us to greatly reduce most systematics. We will discuss the statistical and systematic limits from a recent EDM data run as well as improvements in both our state preparation and detection schemes.

Future searches of an EDM of protons and deuterons at COSY storage ring in Juelich, envision the use of Wien filter acting as spin rotator. Crucial idea is that Wien filter produces spin kicks which give a growth of the EDM signal. In all approaches one starts with the injection of the vertically polarized beam. Radiofrequency Wien filter modulates spin tune of stored particles. If EDM is non-zero this modulation conspires with the EDM-induced rotation of the spin in the motional electric field in the ring and generates the EDM signal - the in-plane horizontal polarization. We discuss the duality between RF spin flipper and RF Wien filter and we argue why spin coherence time is equal for two devices. Another case is static Wien filter with constant fields. Behavior of spin vector is the same, but the machine is operated exactly at imperfection resonance (for protons, G?=2), which drastically decreases spin coherence time. Last case is more promising but it needs supercompensated magnetic lattice, an option which has to be studied further.

Future searches of an EDM of protons and deuterons at COSY storage ring in Juelich, envision the use of Wien filter acting as spin rotator. Crucial idea is that Wien filter produces spin kicks which give a growth of the EDM signal. In all approaches one starts with the injection of the vertically polarized beam. Radiofrequency Wien filter modulates spin tune of stored particles. If EDM is non-zero this modulation conspires with the EDM-induced rotation of the spin in the motional electric field in the ring and generates the EDM signal - the in-plane horizontal polarization. We discuss the duality between RF spin flipper and RF Wien filter and we argue why spin coherence time is equal for two devices. Another case is static Wien filter with constant fields. Behavior of spin vector is the same, but the machine is operated exactly at imperfection resonance (for protons, G?=2), which drastically decreases spin coherence time. Last case is more promising but it needs supercompensated magnetic lattice, an option which has to be studied further.

The design of the storage ring for the deuteron electric dipole moment (EDM) search uses crossed E and B fields to nearly stop the magnetic moment precession of the deuteron in the ring bending magnets. This allows time for the EDM (whose predession is based on E=?vxB) to generate a detectable vertical polarization component [1]. A polarimeter for the EDM ring must monitor continuously and with high statistical precision. Recent tests at COSY-J"ulich have demonstrated high efficiency (˜1.5%) using a thick-walled carbon tube target that also determines the ring aperture. Extraction onto the target was tested using beam position ramping and beam heating with a cluster jet target or a white-noise electric field. Systematic errors were investigated. Continuous monitoring demonstration measurements were made using an RF solenoid whose frequency was ramped through the 1-G? depolarizing resonance.[1] F.J. Farley et al, Phys. Rev. Lett. 93. 052001 (2004).

Improving the electron electric dipole moment (e-EDM) upper limit has been a 40-year battle against systematic effects. Two new weapons in this battle are slow atoms and ground-state electric field quantization, both of which suppress motional magnetic field effects. They have been used effectively in a recently completed e-EDM experiment that is a prototype for a high-sensitivity Cs fountain e-EDM experiment. Electric field quantization of Cs atoms required nulling residual magnetic fields to field-free (nulled) regions, and inducing transitions between closely spaced |mF| levels using separated short pulses in place of oscillatory fields. The possibility of improving the e-EDM limit with a Cs fountain experiment will be discussed.

Magnetic field stabilization is a crucial condition parameter for many kinds of ultra-high precision measurements such as a search for an electric dipole moment (EDM). The instability of magnetic field strength often arises from the drift of current flow in a solenoid coil to generate the magnetic field. For our EDMsearch experiment with maser oscillating diamagnetic 129Xe atoms, we have developed a new stabilized current source based on a feedback system which is devised to correct the amount of current flow measured precisely with high-precision digital multimeter and standard resistor. Using this new current source, we have successfully reduced the drifts of coil current by at least a factor of 100 compared to commercially available current sources.

Magnetic field stabilization is a crucial condition parameter for many kinds of ultra-high precision measurements such as a search for an electric dipole moment (EDM). The instability of magnetic field strength often arises from the drift of current flow in a solenoid coil to generate the magnetic field. For our EDMsearch experiment with maser oscillating diamagnetic 129Xe atoms, we have developed a new stabilized current source based on a feedback system which is devised to correct the amount of current flow measured precisely with high-precision digital multimeter and standard resistor. Using this new current source, we have successfully reduced the drifts of coil current by at least a factor of 100 compared to commercially available current sources.

We are developing an EDMsearch based on laser-cooled and trapped Ra-225 (half-life = 15 d) atoms. Due to octupole deformation of the nucleus, Ra-225 is predicted to be 2-3 orders of magnitude more sensitive to T-violating interactions than Hg-199, which currently sets the most stringent limits in the nuclear sector. Recently, we have succeeded in transferring Ra-226 atoms from a MOT into an optical dipole trap formed by a fiber laser beam at 1550 nm. For the EDM measurement, the cold atoms will be moved into the neighboring vacuum chamber inside magnetic shields where a pair of electrodes apply a 10 kV cm-1electric field. This work is supported by DOE, Office of Nuclear Physics under contract No. DE-AC02-06CH11357.

A computer program designed to provide a number of quantitative analysis tools for high-resolution imaging and electron diffraction data is described. The program includes basic image manipulation, both real space and reciprocal space image processing, Wiener-filtering, symmetry averaging, methods for quantification of electron diffraction patterns and two-dimensional direct methods. The program consists of a number of sub-programs written in a combination of C++, C and Fortran. It can be downloaded either as GNU source code or as binaries and has been compiled and verified on a wide range of platforms, both Unix based and PC's. Elements of the design philosophy as well as future possible extensions are described

The electronedm de is known to be smaller in magnitude than 1.6x10-27e.cm [1]. We will describe progress on an ongoing experiment designed to be sensitive to an electronEDM de as small as 10-29e.cm. The experiment will search for the resulting edm of the Cs atom, proportional to de, using laser-cooled Cs atoms held in an optical dipole force trap. Important features of the experiment include resonant optical cavities to accurately define the trapping laser field, in-vacuum high voltage electrodes, and methods to reduce magnetic noise to low levels, including the use of a novel titanium vacuum chamber [4pt] [1] B. C. Regan et al. Phys. Rev. Lett. 88, 071805 (2002)

The observation of a permanent electric dipole moment (EDM) in a non-degenerate system would indicate violation of time reversal symmetry. ^225Ra atom is a particularly attractive candidate for this search since it has a nuclear spin I=1/2 and has a significant nuclear octupole deformation. This property increases the Schiff moment of the nucleus and therefore enhances the atomic EDM. The half life (t1/2 =14.9 days) of ^225Ra is sufficiently long to perform EDMsearches. Our group has already demonstrated the trapping of laser cooled Ra atoms in a magneto-optical trap (MOT) and transferring them to a far off resonant optical dipole trap (ODT). We will discuss our recent progress on manipulation of ultra cold Ra atoms in the ODT, efforts in improving our laser systems and generation of electric and magnetic fields required for the measurement.

We consider the corrections that arise at one loop when integrating out heavy fields in supersymmetric models. We show that, in type-I see-saw models, complex AN- and BN-terms of the heavy right-handed neutrino give radiative contributions to the neutron EDM, as well as new dominant contributions to the electronEDM. Type-II and type-III see-saw also predict a pure gauge correction that makes complex the masses of the weak gauginos. All the see-saw models can predict observable EDM for the electron and for the neutron in a peculiar ratio.

We consider the corrections that arise at one loop when integrating out heavy fields in supersymmetric models. We show that, in type-I see-saw models, complex A and B terms of the heavy right-handed neutrino give radiative contributions to the neutron EDM, as well as new dominant contributions to the electronEDM. Type-II and type-III see-saw also predict a pure gauge correction that makes complex the masses of the weak gauginos. All the see-saw models can predict observable EDM for the electron and for the neutron in a peculiar ratio.

We consider the corrections that arise at one loop when integrating out heavy fields in supersymmetric models. We show that, in type-I see-saw models, complex A{sub N}- and B{sub N}-terms of the heavy right-handed neutrino give radiative contributions to the neutron EDM, as well as new dominant contributions to the electronEDM. Type-II and type-III see-saw also predict a pure gauge correction that makes complex the masses of the weak gauginos. All the see-saw models can predict observable EDM for the electron and for the neutron in a peculiar ratio.

Observation of a permanent electric dipole moment of the electron (eEDM) would imply CP violating effects not contained in the Standard Model. We describe the state preparation and spectroscopy that will be used to measure the eEDM. Cesium atoms are guided into a measurement chamber, where they are laser-cooled and trapped in a pair of parallel one-dimensional optical lattices. The lattices thread three specially coated glass electric field plates. The measurement chamber is surrounded by a four layer magnetic shield inside of which eight magnetic field coils control the bias and gradient magnetic fields. A series of microwave and low frequency magnetic field pulses transfer the atoms into a superposition state that is sensitive to the eEDM signal. A measurement of the eEDM using neutral cesium atoms can obtain an ultimate shot noise limit of 3x10-30 e-cm.

The ACME collaboration aims to measure the eEDM via Ramsey spectroscopy of a cryogenic beam of ThO molecules in their metastable H state. This thesis describes the launch of this new experimental effort. A set of diode lasers has been built to address all the necessary ThO transitions. The laser frequencies were stabilized to a stable reference laser via a Fabry-Perot transfer cavity. A measurement of the magnetic dipole moment of the H state has been performed that is complementary to a previous measurement by the collaboration. This value is important for determining the sensitivity of the H state to magnetic fields, which can be a source of noise and systematic errors in the eEDM measurement. Experimental efforts to prepare the coherent superposition of the M=+/-1 Zeeman sublevels in the H, J=1 state that is the starting point of the eEDM experiment using transitions to the G state resulted in a better understanding of transitions between O-doublet states in an electric field. This led to a new technique for normalizing out shot-to-shot fluctuations in the molecular beam flux, which has also been demonstrated experimentally.

CERN, the European Laboratory for Particle Physics, located in Geneva -Switzerland, is currently building the LHC (Large Hadron Collider), a 27 km particle accelerator. The equipment life-cycle management of this project is provided by the Engineering and Equipment Data Management System (EDMS) Service. Using an Oracle database, it supports the management and follow-up of different kinds of documentation through the whole life cycle of the LHC project: design, manufacturing, installation, commissioning data etc... The equipment data collection phase is now slowing down and the project is getting closer to the 'As-Built' phase: the phase of the project consuming and exploring the large volumes of data stored since 1996. Searching through millions of items of information (documents, equipment parts, operations...) multiplied by dozens of points of view (operators, maintainers...) requires an efficient and flexible search engine. This paper describes the process followed by the team to implement the search engine for the LHC As-built project in the EDMS Service. The emphasis is put on the design decision to decouple the search engine from any user interface, potentially enabling other systems to also use it. Projections, algorithms, and the planned implementation are described in this paper. The implementation of the first version started in early 2007

CERN, the European Laboratory for Particle Physics, located in Geneva -Switzerland, is currently building the LHC (Large Hadron Collider), a 27 km particle accelerator. The equipment life-cycle management of this project is provided by the Engineering and Equipment Data Management System (EDMS [1] [2]) Service. Using an Oracle database, it supports the management and follow-up of different kinds of documentation through the whole life cycle of the LHC project: design, manufacturing, installation, commissioning data etc... The equipment data collection phase is now slowing down and the project is getting closer to the 'As-Built' phase: the phase of the project consuming and exploring the large volumes of data stored since 1996. Searching through millions of items of information (documents, equipment parts, operations...) multiplied by dozens of points of view (operators, maintainers...) requires an efficient and flexible search engine. This paper describes the process followed by the team to implement the search engine for the LHC As-built project in the EDMS Service. The emphasis is put on the design decision to decouple the search engine from any user interface, potentially enabling other systems to also use it. Projections, algorithms, and the planned implementation are described in this paper. The implementation of the first version started in early 2007.

The present status of an active spin maser which is being developed for an experimental search for {sup 129}Xe atomic electric dipole moment (EDM) is presented. In order to realize the long term stability of maser frequency, systematic effects for the spin maser operation were investigated. The correlations in the maser frequency with the solenoid current, the environmental field and the cell temperature were found. With the solenoid current and environmental field being stabilized and the cell temperature lowered, a frequency precision of 7.9 nHz has been achieved for the maser operation.

The present status of an active spin maser which is being developed for an experimental search for 129Xe atomic electric dipole moment (EDM) is presented. In order to realize the long term stability of maser frequency, systematic effects for the spin maser operation were investigated. The correlations in the maser frequency with the solenoid current, the environmental field and the cell temperature were found. With the solenoid current and environmental field being stabilized and the cell temperature lowered, a frequency precision of 7.9 nHz has been achieved for the maser operation.

The JILA electron electric dipole moment (eEDM) experiment will use a low-lying, metastable ^3?_1 state in trapped molecular ions of HfF^+ or ThF^+. Prior to this work, the low-lying states of these molecules had been investigated by PFI-ZEKE spectroscopy. However, there were no detailed studies of the electronic structure. The recently developed technique of frequency comb velocity modulation spectroscopy (VMS) provides broad-bandwidth, high-resolution, ion-sensitive spectroscopy, allowing the acquisition of 150 cm^{-1} of continuous spectra in 30 minutes over 1500 simultaneous channels. By supplementing this technique with cw-laser VMS, we have investigated the electronic structure of HfF^+ in the frequency range of 9950 to 14600 cm^{-1}, accurately fitting and assigning 16 rovibronic transitions involving 8 different electronic states including the X^1?^+ and a^3?_1 states. In addition, an observed ^3?_{0+} state with coupling to both the X and a states has been used in the actual eEDM experiment to coherently transfer population from the rovibronic ground state of HfF^+ to the eEDM science state. Furthermore, we report on current efforts of applying frequency comb VMS at 700 - 900 nm to the study of ThF^+, which has a lower energy ^3?_1 state and a greater effective electric field, and will provide increased sensitivity for a measurement of the eEDM. A. E. Leanhardt et. al., Journal of Molecular Spectroscopy 270, 1-25 (2011). B. J. Barker, I. O. Antonov, M. C. Heaven, K. A. Peterson, Journal of Chemical Physics 136, 104305 (2012). L. C. Sinclair, K. C. Cossel, T. Coffey, J. Ye, E. A. Cornell, Physical Review Letters 107, 093002 (2011). K.C. Cossel et. al., Chemical Physics Letters 546, 1-11 (2012).

Recently strong electric fields (up to 109 V/cm) have been discovered, which affect the neutrons moving in noncentrosymmetric crystals. Such fields allow for new polarization phenomena in the neutron diffraction and in the optics and provide, for instance, a new method of a search for the neutron electric dipole moment (EDM). A strong interplanar electric field of the crystal and a sufficiently long time for the neutron passage through the crystal for Bragg angle close to ?/2 in the case of Laue diffraction make it possible to exceed the sensitivity achieved with the magnetic resonance method using ultra cold neutrons (UCN method). The pilot setup has been created and mounted at the neutron beam at the WWR-M reactor in Gatchina. It allows to study the optics and the dynamical diffraction of polarized neutrons in thick (1-10 cm) crystals, using the direct diffraction beam and Bragg angles close to 90 deg. . The first experimental results are discussed on observing new effects in both the Laue diffraction and the optics of cold neutrons. These results confirm the opportunity to increase more than by an order of magnitude the sensitivity of the method to neutron EDM, using the diffraction angles close to 90 deg. and give a real prospect to exceed the sensitivity of the UCN method

Heavy polar diatomic molecules are the primary tools for searching for the T-violating permanent electric dipole moment of the electron (eEDM). Valence electrons in some molecules experience extremely large effective electric fields due to relativistic interactions. These large effective electric fields are crucial to the success of polar-molecule-based eEDMsearch experiments. Here we report on the results of relativistic ab initio calculations of the effective electric fields in a series of molecules that are highly sensitive to an eEDM, the mercury monohalides (HgF, HgCl, HgBr,and HgI). We study the influence of the halide anions on effective electric field, and identify HgBr and HgI as interesting candidates for future electric dipole moment search experiments.

We study the electric dipole moments (EDMs) of fermions in the standard model supplemented with right-handed neutrinos and its extension including the neutrino seesaw mechanism under the framework of minimal flavor violation (MFV). In the quark sector, we find that the current experimental bound on the neutron EDM does not yield a significant restriction on the scale of MFV. In addition, we consider how MFV may affect the contribution of the strong theta-term to the neutron EDM. For the leptons, the existing EDM data also do not lead to strict limits if neutrinos are Dirac particles. On the other hand, if neutrinos are Majorana in nature, we find that the constraints become substantially stronger. Moreover, the results of the latest search for the electronEDM by the ACME Collaboration are sensitive to the MFV scale of order a few hundred GeV or higher. We also look at constraints from CP -violating electron-nucleon interactions that have been probed in atomic and molecular EDMsearches.

The observation of a permanent electric dipole moment (EDM) at current experimentally accessible levels would provide clear evidence of physics beyond the Standard Model. EDMs violate CP symmetry, making them a possible route to explaining the size of the observed baryon asymmetry in the universe. The Radon EDM Experiment aims to search for an EDM in radon isotopes whose sensitivity to CP-odd interactions is enhanced by octupole-deformed nuclei. A prototype apparatus currently installed in the ISAC hall at TRIUMF includes a gas handling system to move radon from a collection foil to a measurement cell and auxiliary equipment for polarization diagnostics and validation. The features and capabilities of the apparatus are described and an overview of the experimental design for a gamma-ray-anisotropy based EDM measurement is provided.

Observation of a nonzero EDM would imply CP violation beyond the Standard Model. Additional sources of CP violation are expected to help explain the matter-antimatter asymmetry observed in our universe and naturally arise in extensions to the standard model such as supersymmetry. Our group has recently reported a new upper limit: |dHg| EDM of ^199Hg. The experiment compared the spin precession frequencies in four spin-polarized Hg vapor cells: two cells lie in parallel magnetic and anti-parallel electric fields, resulting in EDM-sensitive spin precession while the remaining two cells, at zero electric field, serve to cancel noise generated by magnetic field gradients and test for systematic errors. A frequency shift, linear in the applied electric field, due to the Stark mixing of atomic states has been identified and measured. A description of the EDM experiment and measurements that led to our recent result will be presented. )

The T-odd phenomenon of induction of the magnetic field by a static electric field provides to study the electronEDM and constants of T-odd, P-odd interaction of an electron with a nucleus. Measurement of this magnetic field for ferroelectric materials (like PbTiO_3) at the level B~3 10^{-18} G allows to derive the electric dipole moment of an electron at the level d_e ~ 10^{-30} e cm and the constant of T-odd scalar weak interaction of an electron with a nucleus at the level k_1^{nuc}10^{-9}. The atomic magnetometry makes possible to measure fields ~ 10^{-13} G/\\sqrt{Hz} now. This means that for 10 days operation one can expect to obtain B at the level B ~ 10^{-16}G, and, therefore, the limits for d_e in PbTiO_3 at the level d_e ~ 10^{-28} and k_1^{nuc}~10^{-7}. that makes the discussed method beneficial for measuring d_e and k_1^{nuc}.

The metastable excited state a(1)[3?+] of PbO is proposed as a candidate system in which to search for an electron electric dipole moment (EDM). It is shown that the sensitivity to an electronEDM (de) could reach 10-31 e·cm--an improvement of >104 over the current limit. Observation of an electronEDM would provide definitive evidence for physics beyond the standard model, and many currently favored theories predict vertical bar de vertical bar>10-31. The sensitivity of the proposed technique arises from a combination of several unique properties of PbO, which simultaneously provide a large EDM enhancement factor, narrow magnetic resonance lines, and high counting rates. The structure of the nearly degenerate ?-doublet system in PbO permits the use of unique and powerful techniques for the rejection of systematic effects

A prototype experiment to measure the neutron electric dipole moment (nEDM) by spin-rotation in a non-centrosymmetric crystal in Laue geometry was carried out in order to investigate the statistical sensitivity and systematic effects of the method. The statistical sensitivity to the nEDM was about $6\\cdot 10^{-24}$ e$\\cdot $cm per day and can be improved by one order of magnitude for the full scale setup. Systematics was limited by the homogeneity of the magnetic field in the crystal region and by a new kind of spin rotation effect. We attribute this effect to a difference of the two Bloch waves amplitudes in the crystal, which is caused by the presence of a small crystal deformation due to a temperature gradient. In a revised scheme of the experiment, this effect could be exploited for a purposeful manipulation of the Bloch waves.

It is shown that in the experiments for search of EDM of an electron (atom, molecule) the T-odd magnetic moment induced by an electric field and the T-odd electric dipole moment induced by a magnetic field will be also measured. It is discussed how to distinguish these contributions.

A nuclear spin maser is operated at a low static field through an active feedback scheme based on an optical nuclear spin detection and succeeding spin control by a transverse field application. The frequency stability of this optical-coupling spin maser is improved by installation of a low-noise current source for a solenoid magnet producing a static magnetic field in the maser operation. Experimental devices for application of the maser to EDM experiment are being developed.

A nuclear spin maser is operated at a low static field through an active feedback scheme based on an optical nuclear spin detection and succeeding spin control by a transverse field application. The frequency stability of this optical-coupling spin maser is improved by installation of a low-noise current source for a solenoid magnet producing a static magnetic field in the maser operation. Experimental devices for application of the maser to EDM experiment are being developed.

Within the framework of N=1 gauged supergravity, using a phenomenological model which can be obtained locally as a Swiss-Cheese Calabi-Yau string-theoretic compactification with a mobile D3-brane localized on a nearly sLag three-cycle in the Calabi-Yau and fluxed stacks of wrapped D7-branes, and which provides a natural realization of mu-Split SUSY, we show that in addition to getting a significant value of electron/neutron EDM d_{e,n}/e at two-loop level, one can obtain a sizable contribution of d_{e,n}/e even at one-loop level. We obtain d_{e}/e ~ O(10^{-29}) cm from two-loop diagrams involving heavy sfermions and a light Higgs, and d_{e}/e ~ O(10^{-32}) cm from one-loop diagram involving heavy chargino and a light Higgs. Also, d_{n}/e ~ O(10^{-33}) cm from one-loop diagram involving SM-like quarks and Higgs. Next, by considering a Barr-Zee diagram involving W bosons and Higgs, and conjecturing that the CP-violating phase can appear from a linear combination of Higgs doublet obtained in the context of mu-sp...

A non-zero permanent electric dipole moment (EDM) of an electron would violate parity and time-reversal symmetries. Non-zero EDMs are predicted in the standard model, but are unobservably small. New physics incorporating new particles and new CP-violating phases can lead, through radiative corrections, to dramatic enhancements of the electronEDM, to within a few orders of magnitude of the current experimental limit. A new approach to electronEDMsearches using molecular ions stored in a table-top electrostatic storage ring is described. Molecular ions with long-lived paramagnetic states such as WN^+ can be injected and stored in larger numbers and with longer coherence times than competing experiments, leading to high sensitivity to an electronEDM. Systematic effects mimicking an EDM such as those due to motional magnetic fields and geometric phases are found not to limit the approach in the short term. Sensitivities of ?|de| 10-30 e.cm/day, an improvement by three orders of magnitude, appear possible under conservative conditions.

The main purpose of this paper is to present NPP's plans regarding the on-going project that started in November 2011, and that is related to the establishment of ''Internal Rules'' and EDMS - Electronic Document Management System.The term ''Internal Rules'' has been directly translated from Slovenian language (''Notranja pravila'') and adopted from the translated version of appropriate Slovenian national codes (ZVDAGA [1] in Slovenian language or PDAAIA [2] in English version). ''Internal Rules on capture and storage of materials in digital form'' refer to the rules adopted by a person as his/her internal act with reference to storage of his/her material. The main purpose for the establishment of the Internal Rules is to be able to justify that Krsko NPP is organized in compliance with the national codes covering that subject and strictly performing according to those Internal Rules. Once a Slovenian company achieves recognized and registered status in accordance with the Internal Rules document that has been certified and approved by the ARS (Archives of the Republic Slovenia), such company can utilize e-documents in the same way as they would utilize physical documents. Furthermore, a Slovenian company with approved Internal Rules can use e-documents in any legal aspect associated with the document's life cycle and the document's content as they would use the physical document or an authorized and approved copy of the physical document. Related to the nuclear regulatory background, NEK operates in compliance with the Slovenian legislation and also the US codes, regulations and guidelines; therefore, regarding the NPP specific documents, the Internal Rules and EDMS must also be in compliance with them. Since early 1990's, NEK has implemented document/records management system oriented towards supporting storage and management of physical documents/records and controlling distribution of active document copies. Document/records management system was supported by two applications (DCM-Document Control Module andQRM-Quality Records Management). Both computer applications were designed in order to fulfil requirements of the criteria VI (Document Control) and criteria XVII (Quality Assurance Records) of the US code [3]. In order to prevent confusion, clarifications regarding the terms ''documents'' and ''records'' are the following: Documents are an organized collection of information or objects that can be treated as a unit. A document may or may not meet the definition of a record. Records are sub-set of all information or all documents held by a person or organisation. Records present information, regardless of physical form or characteristics, appropriate for preservation as evidence of the organization, functions, policies, decisions, procedures, operations, or other activities of the organization. Examples of where this information may reside are books, papers, maps, photographs, machine-readable electronic files, or other documentary materials. Quality Assurance Records related to the NPPs are the records which furnish documentary evidence of the quality of items and activities affecting quality. For the purpose of the standards [4] and [5], a document is considered a quality assurance record when it has been completed.(author).

We analyze the electric dipole moment of the electron ($d_e$), of the neutron ($d_n$) and of the muon ($d_{\\mu}$) using the cancellation mechanism in the presence of nonuniversalities of the soft breaking parameters. It is shown that the nonuniversalities in the slepton sector produce a strong violation of the scaling relation $d_{\\mu}/d_e\\simeq m_{\\mu}/m_e$ in the cancellation region. An analysis of $d_e, d_n$ and $d_{\\mu}$ under the constraints of the current experimental limits on $d_e$ and $d_n$ and under the constraints of the recent Brookhaven result on $g_{\\mu}-2$ shows that in the non-scaling region $d_{\\mu}$ can be as large as ($10^{-24}-10^{-23}$)ecm and thus within reach of the recently proposed Brookhaven experiment for a sensitive search for $d_{\\mu}$ at the level of $10^{-24}$ ecm.

We report results of an experimental search for the permanent Electric Dipole Moment (EDM) of the electron using a solid state system. The experiment uses a paramagnetic insulator (gadolinium gallium garnet) with a large magnetic response at low temperatures. The presence of the electronEDM leads to a finite magnetization when the garnet sample is subjected to a strong electric field. The resulting magnetization can be measured using a superconducting quantum interference device (SQUID) as a magnetometer. With considerable efforts made towards controlling various sources of systematic effects, the experiment is currently free of spurious signals larger than the SQUID noise. We report the value of electronEDM of (-5.57 ± 7.98 ± 0.12) × 10-25e-cm with 120 hours of data.

We report a new upper limit on the electric dipole moment (EDM) of the electron of d{sub e} = 0.1 {plus minus} 3.2 {times} 10{sup {minus}26} e-cm. This precision is one hundred times better than any previously published limit and a factor of two better than that of unofficial reports. Recently there has been a great deal of theoretical interest in the possibility of a non-zero electronEDM. Models such as the left-right-symmetric Standard Model and an off-standard'' model with new heavy neutrinos are constrained by the new limit on d{sub e}. A non-zero electronEDM would violate the time reversal and parity space-time symmetries. T-violation was observed in neutral kaon decay and is still not fully explained by the Standard Model. Our experimental technique involves searching for an energy shift, linear in applied electric field, between the m{sub F} = 1 and m{sub F} = {minus}1 magnetic sublevels of the F=1 hyperfine level of the 6{sup 2}P{sub 1/2} ground state of atomic thallium. If the electron has a non-zero EDM, this thallium state will exhibit an atomic electric dipole moment that is roughly 600 times larger. The energy shift is detected with the technique of magnetic resonance spectroscopy, employing separated oscillating fields, applied to an atomic beam of thallium. In the approach, any relative phase-shift between the m{sub F} = {plus minus}1 components of the F=1 wavefunction acquired by the atom as it travels through an electric field is detected through interference with two separate oscillating magnetic fields located on either side of the electric field. The new level of precision is achieved through several improvements on previous experiments including employment of a vertical apparatus, two opposing atomic beams, and optical pumping for atomic state selection and analysis.

We present results of the first experiment to probe for the electric dipole moment (EDM) of the electron using an $\\Omega$-doublet state in a polar molecule. If the molecule is both massive and has a large molecular-fixed frame dipole moment, then the $\\Omega$-doublet states have the potential to greatly increase the sensitivity of experiments searching for the EDM while also allowing for new methods of systematic error rejection. Here, we use the metastable $a(1)^3\\Sigma^+$ state of lead monoxide (PbO) to probe for the electronEDM. Our best fit for the electronEDM of $d_e = (-4.4\\pm9.5_\\text{stat}\\pm1.8_\\text{syst})\\times10^{-27}\\ecm$ allows us to place an upper limit on the magnitude of the EDM of $|d_e|<1.7\\times10^{-26}\\ecm$ (90% confidence). While this is less stringent than limits from other, previous experiments, our work emphasizes the systematic error rejection properties associated with the $\\Omega$-doublet level structure. The results should inform the work of other, ongoing experiments that u...

The search for CP violating forces between nucleons in the so-called axion window of force ranges ? between 2 × 10-5 m and 0.02 m is interesting because only little experimental information is available there. Axionlike particles would induce a pseudo-magnetic field for neutrons close to bulk matter. A laboratory search investigates neutron spin precession close to a heavy mirror using ultracold neutrons in a magnetic resonance spectrometer. From the absence of a shift of the magnetic resonance we established new constraints on the coupling strength of axion-like particles in terms of the product g s g p of scalar and pseudo-scalar dimensionless constants, as a function of the force range ?, g s g p ?2 ? 2 × 10-21 [cm2] (C.L.95%) for 10-4 cm < ? < 1 cm. For 0.1 cm < ? < 1 cm previous limits are improved by 4 to 5 orders of magnitude.

The search for CP violating forces between nucleons in the so-called axion window of force ranges lam between 2x10^-5 m and 0.02 m is interesting because only little experimental information is available there. Axion-like particles would induce a pseudo-magnetic field for neutrons close to bulk matter. A laboratory search investigates neutron spin precession close to a heavy mirror using ultracold neutrons in a magnetic resonance spectrometer. From the absence of a shift of the magnetic resonance we established new constraints on the coupling strength of axion-like particles in terms of the product gs x gp of scalar and pseudo-scalar dimensionless constants, as a function of the force range lam, gs x gp x lam^2 <= 2x10-21 [cm^2] (C.L.95%) for 10^-4 cm < lam < 1 cm. For 0.1 cm < lam < 1 cm previous limits are improved by 4 to 5 orders of magnitude.

We present recent progress in construction of an ultra-high precision liquid ^129Xe NMR probe designed to look for a permanent EDM of an atomic xenon. High spin density and dielectric strength in the condensed phase make an atomic liquid an attractive candidate for search for an EDM. We employ low-transition temperature (Tc) superconducting quantum interference devices (SQUIDs) for detection of low frequency (˜100 Hz) Larmor precession of ^129Xe and measurement of magnetic field fluctuation. We shield ambient magnetic field noise by a superconducting magnetic shield immersed in a liquid helium cryostat. A magnetic field resolution better than 1 fT/Hz^1/2 and ^129Xe frequency resolution on the order of 1 nH/Hz^1/2 are expected from this design. Currently experiments are under way in a prototype setup to measure the signal-to-noise ratio and frequency stability in SQUID-detected ^129Xe NMR, and to determine low-temperature leakage current under high voltage in a sapphire-based liquid xenon cell.

The possibility to measure an electric dipole moment (EDM) of nuclei in the range $10^{-27} \\div 10^{-32}$ $e \\cdot cm$ in experiments for search of time-reversal violating generation of magnetic and electric fields is discussed.

Strong correlations between leptogenesis and low energy CP violating leptonic processes have been shown by us to exist in the minimal left-right symmetric model with spontaneous CP violation. In this note, we investigate the implications of this model for the electric dipole moment of the electron. With an additional broken U(1)_H symmetry, the seesaw scale can be lowered to close to the electroweak scale. This additional symmetry also makes the connection between CP violation in quark sector to that in the lepton sector possible.

The usual transformations of the three-dimensional (3D) fields E and B that are found in [1] ([1] A. Einstein, Ann. Physik \\17, 891 (1905)) are always considered to be the relativistically correct Lorentz transformations (LT) of E and B. However, as proved in, e.g., [2] ([2] T. Ivezi\\'c, Found. Phys. Lett. 18, 301 (2005)), these transformations drastically differ from the LT of the relativistically correct 4D electric and magnetic fields. In this paper a simple proof of that difference will be presented and the consequences for EDM experiments and for some quantum phase shifts experiments are briefly examined. In all such experiments the usual 3D quantities, e.g., E, B, ... are measured and their relativistically incorrect transformations are used, but not the relativistically correct 4D geometric quantities, e.g., E^a, B^a, ... and their LT.

We are very pleased to announce the arrival of a brand new EDMS: EDMS 6. The CERN Engineering and Equipment Data Management Service just got better than ever! EDMS is the de facto interface for all engineering related data and more. Currently there are more than 1.2 million documents and nearly 2 million files stored in EDMS. What’s new? The first thing you will notice is the look and feel of EDMS 6; the new design not only makes it more modern but also more intuitive, so that the system is easier to use, regardless of your experience with EDMS. Whilst we have kept the key concepts, we have introduced more functionality and improved navigation within the interface, allowing for better performance to help you in your daily work. We have also added a personal slant to EDMS 6 so that you can now customise your list of favourite objects. Modifying data in EDMS is much simpler, allowing you to view all object data in a single window. More functionality will be added in the ...

We address a number of issues regarding solid-state electron electric-dipole moment (EDM) experiments, focusing on gadolinium-iron garnet [(GdIG) chemical formula Gd3Fe5O12 ] as a possible sample material. GdIG maintains its high magnetic susceptibility down to 4.2 K, which enhances the EDM-induced magnetization of a sample placed in an electric field. We estimate that lattice polarizability gives rise to an EDM enhancement factor of approximately 20. We also calculate the effect of the demagnetizing field for various sample geometries and permeabilities. Measurements of intrinsic GdIG magnetization noise are presented, and the fluctuation-dissipation theorem is used to compare our data with the measurements of the imaginary part of GdIG permeability at 4.2 K, showing good agreement above frequencies of a few hertz. We also observe how the demagnetizing field suppresses the noise-induced magnetic flux, confirming our calculations. The statistical sensitivity of an EDMsearch based on a solid GdIG sample is estimated to be on the same level as the present experimental limit. Such a measurement would be valuable given the completely different methods and systematics involved. The most significant systematics in such an experiment are the magnetic hysteresis and the magnetoelectric effect. Our analysis shows that it should be possible to control these at the level of statistical sensitivity.

We address a number of issues regarding solid state electron electric dipole moment (EDM) experiments, focusing on gadolinium iron garnet (abbreviated GdIG, chemical formula Gd$_3$Fe$_5$O$_{12}$) as a possible sample material. GdIG maintains its high magnetic susceptibility down to 4.2 K, which enhances the EDM-induced magnetization of a sample placed in an electric field. We estimate that lattice polarizability gives rise to an EDM enhancement factor of approximately 20. We also calculate the effect of the demagnetizing field for various sample geometries and permeabilities. Measurements of intrinsic GdIG magnetization noise are presented, and the fluctuation-dissipation theorem is used to compare our data with the measurements of the imaginary part of GdIG permeability at 4.2 K, showing good agreement above frequencies of a few hertz. We also observe how the demagnetizing field suppresses the noise-induced magnetic flux, confirming our calculations. The statistical sensitivity of an EDMsearch based on a so...

Full Text Available The paper presents investigation on search in electronic catalogues. The chosen problem domain is the search system in the electronic catalogue of Lithuanian Academic Libraries. The catalogue uses ALEPH system with MARC21 bibliographic format. The article presents analysis of problems pertaining to the current search engine and user expectations related to the search system of the electronic catalogue of academic libraries. Subsequent to analysis, the research paper presents the architecture for a semantic search system in the electronic catalogue that uses search process designed to improve search results for users.

The electric dipole moment of the neutron, leptons, and atoms provide a unique window to Physics Beyond the Standard Model. They are currently developing a new neutron EDM experiment (the nEDM Experiment). This experiment, which will be run at the 8.9 {angstrom} Neutron Line at the Fundamental Neutron Physics Beamline (FNPB) at the Spallation Neutron Source (SNS) at the Oak Ridge National Laboratory, will search for the neutron EDM with a sensitivity two orders of magnitude higher than the present limit. In this paper, the motivation for the experiment, the experimental method, and the present status of the experiment are discussed.

In 1968, F.L. Shapiro published the suggestion that one could search for an electronEDM by applying a strong electric field to a substance that has an unpaired electron spin; at low temperature, the EDM interaction would lead to a net sample magnetization that can be detected with a SQUID magnetometer. One experimental EDMsearch based on this technique was published, and for a number of reasons including high sample conductivity, high operating temperature, and limited SQUID technology, the result was not particularly sensitive compared to other experiments in the late 1970's. Advances in SQUID and conventional magnetometery had led us to reconsider this type of experiment, which can be extended to searches and tests other than EDMs (e.g., test of Lorentz invariance). In addition, the complementary measurement of an EDM-induced sample electric polarization due to application of a magnetic field to a paramagnetic sample might be effective using modern ultrasensitive charge measurement techniques. A possible ...

An experiment to search for the electron electric dipole moment (eEDM) on the metastable H(3)?1 state of ThO molecule was proposed and now prepared by the ACME Collaboration [http://www.electronedm.org]. To interpret the experiment in terms of eEDM and dimensionless constant kT, P characterizing the strength of the T,P-odd pseudoscalar-scalar electron-nucleus neutral current interaction, an accurate theoretical study of an effective electric field on electron, Eeff, and a parameter of the T,P-odd pseudoscalar-scalar interaction, WT, P, in ThO is required. We report our results for Eeff (84 GV/cm) and WT, P (116 kHz) together with the hyperfine structure constant, molecule frame dipole moment, and H(3)?1 ? X(1)?(+) transition energy, which can serve as a measure of reliability of the obtained Eeff and WT, P values. Besides, our results include a parity assignment and evaluation of the electric-field dependence for the magnetic g factors in the ?-doublets of H(3)?1. PMID:24329049

An experiment to search for the electron electric dipole moment (eEDM) on the metastable H{sup 3}?{sub 1} state of ThO molecule was proposed and now prepared by the ACME Collaboration [ http://www.electronedm.org ]. To interpret the experiment in terms of eEDM and dimensionless constant k{sub T,} {sub P} characterizing the strength of the T,P-odd pseudoscalar–scalar electron–nucleus neutral current interaction, an accurate theoretical study of an effective electric field on electron, E{sub eff}, and a parameter of the T,P-odd pseudoscalar–scalar interaction, W{sub T,} {sub P}, in ThO is required. We report our results for E{sub eff} (84 GV/cm) and W{sub T,} {sub P} (116 kHz) together with the hyperfine structure constant, molecule frame dipole moment, and H{sup 3}?{sub 1} ? X{sup 1}?{sup +} transition energy, which can serve as a measure of reliability of the obtained E{sub eff} and W{sub T,} {sub P} values. Besides, our results include a parity assignment and evaluation of the electric-field dependence for the magnetic g factors in the ?-doublets of H{sup 3}?{sub 1}.

Full Text Available Recently Educational Data Mining (EDM is successful in attracting a great deal of attention of researchers. It is an emerging multidisciplinary research area. Educational Data Mining (EDM is the process of discovering useful information from raw data generated and collected from educational systems which can be used by the different stakeholders. In EDM different techniques and methods for exploring data originating from various educational information systems can be developed. It is rich application area for data mining as well as a learning science, also due to the growing availability of educational data. EDM contributes towards the study of how students can learn and the settings in which they learn. It enables data-driven decision making for improving the current educational practice and learning material. The objective of this paper is to present a brief overview of EDM and to observe the development in the field of EDM.

Recently Educational Data Mining (EDM) is successful in attracting a great deal of attention of researchers. It is an emerging multidisciplinary research area. Educational Data Mining (EDM) is the process of discovering useful information from raw data generated and collected from educational systems which can be used by the different stakeholders. In EDM different techniques and methods for exploring data originating from various educational information systems can be developed. It is rich a...

This new site, currently a pilot service, will soon replace the US Trademark Search Database. TESS allows the general public to search and retrieve trademark application and registration information, using the same text and image database provided to examining attorneys at the US Patent and Trademark Office. Users have three search options, a simple Structured Form Search, a more advanced Free Form Search, and a Browse Dictionary option, which allows "users to scan through the search indices to see indexed terms around a specific search term and provides the counts of occurrences for those indexed terms." Initial returns include Serial Number, Word Mark, and Live/Dead Indicator. Each links to a more detailed record which includes Filing Date, Owner, Type of Mark, and when appropriate, an image. A sample search for "beer" returned over 11,000 returns, while one for "software" produced over 150,000 hits. Search help, a glossary, and a FAQ are provided.

The metastable $H^3\\Delta_1$ state of ThO molecule was proposed in [E. R. Meyer and J. L. Bohn, Phys.Rev.A {\\bf78}, 010502 (2008)] to search for the electron electric dipole moment (\\eEDM) and the ThO beam experiment is now in the final stage of preparation by the ACME collaboration [http://www.electronedm.org]. To interpret the experiment in terms of \\eEDM\\ an accurate theoretical study of effective electric field on electron, \\Eeff, in the molecule is required. We report calculation of \\Eeff\\ (our final value is 84 GV/cm) together with the hyperfine structure constant, molecule frame dipole moment and $H^3\\Delta_1\\to X^1\\Sigma^+$ transition energy, which can serve as a measure of reliability of the obtained \\Eeff\\ value. Besides, our results include a parity assignment and evaluation of the electric-field dependence for the magnetic $g$ factors for the $\\Omega$-doublets of $H^3\\Delta_1$.

The search for the P,T-parity non-conservation (PNC) effects is of fundamental importance in physics. Experiments are performed on T1F and YbF, and are prepared on PbO and HgH molecules. Recently some new approaches were suggested, such as the search for P,T-odd effects in liquid xenon and on HI+ molecular ion. For preparation and interpretation of these experiments high-precision calculations of the electronic structure are required. Recently developed theoretical methods allow one to analyze the atomic-molecular systems from the point of enhancement of P,T-odd effects and recommend such or another system as a prospective candidate. We calculated enhancement factor for electronEDM in the ground state of HI+ molecular ion, required for experiment of new type on electronEDMsearch. The results of calculations of P,T-odd effects in liquid xenon are also discussed.

When Christophe Seith from the company Cegelec sat down to work on 14 May 2009 at 10:09 a.m. to create the EDMS document entitled "Rapport tournée PH semaine 20", little did he know that he would be the proud creator of the millionth EDMS document and the happy prize winner of a celebratory bottle of champagne to mark the occasion. In the run up to the creation of the millionth EDMS document the EDMS team had been closely monitoring the steady rise in the EDMS number generator, so as to ensure the switch from the six figured i.d. to seven figures would run smoothly and of course, to be able to congratulate the creator of the millionth EDMS document. From left to right: Stephan Petit (GS-ASE- EDS Section Leader), Christophe Delamare (GS- ASE Group Leader), Christophe Seith, creator of the millionth EDMS document, David Widegren, (GS-ASE- EPS Section Leader). The millionth EDMS document. For t...

New sources of CP violation beyond the Standard Model may help the scenario of electroweak baryogenesis (EWB) to account for the baryon asymmetry of the universe, and may be detectable in searches for permanent electric dipole moments of fundamental particles. In this talk, I focus on the calculation of the sources and relaxation rates in the transport equations for particle densities in the closed time path formalism of quantum field theory, suitable for the finite temperature and out-of-equilibrium conditions present at the electroweak phase transition. Applying the methods of closed time-path quantum field theory to derive transport equations relevant for EWB in the MSSM, we find regions of the parameter space where generation of the baryon asymmetry is resonantly enhanced, allowing successful baryogenesis with CP-violating phases small enough to be consistent with experimental limits on electron and neutron EDMs

A search for the supersymmetric partners of the electron was made assuming different photino masses. If both types of scalar electrons have an equal mass and the photino is massless, then the lower limit of the scalar electron mass was found to be 25.2 GeV/c2, whereas, if the scalar electrons have different masses, the lower limits is 21.8 GeV/c2. (orig.)

Experimentally observable electric dipole moments (EDMs) are predicted, by nearly all extensions of the Standard Model, to arise from CP-violating couplings to new undiscovered particles in the 0.1 TeV to >10 TeV range. EDMs are widely anticipated and not yet observed. Their discovery would motivate a new generation of particle accelerators. Steps towards a new Cs cold-atom fountain EDM experiment to discover or rule out an electronEDM a factor of 100 below the present limit will be described. Included are: glass electric field plates and vacuum chamber to suppress magnetic Johnson noise, electric field quantization to suppress motional magnetic field systematics, and multiple quantum transitions to enhance sensitivity.

Extrachromosomal DNA maintenance (EDM) is an important process in molecular breeding and for various applications in the construction of genetically engineered microbes. Here we describe a novel Bacillus subtilis gene involved in EDM function called edmS (formerly pgsE). Functional gene regions were identified using molecular genetics techniques. We found that EdmS is a membrane-associated protein that is crucial for EDM. We also determined that EdmS can change a plasmid vector with an unstable replicon and worse-than-random segregation into one with better-than-random segregation, suggesting that the protein functions in the declustering and/or partitioning of episomes. EdmS has two distinct domains: an N-terminal membrane-anchoring domain and a C-terminal assembly accelerator-like structure, and mutational analysis of edmS revealed that both domains are essential for EDM. Further studies using cells of Bacillus megaterium and itsedmS (formerly capE) gene implied that EdmS has potential as a molecular probe for exploring novel EDM systems. PMID:23583563

We derive electric dipole moment (EDM) constraints on possible new macroscopic time reversal and parity violating (TVPV) spin-dependent forces. These constraints are compared to those derived from direct searches in fifth-force experiments and from combining laboratory searches with astrophysical bounds on stellar energy loss. For axion-mediated TVPV spin-dependent forces, EDM constraints dominate over fifth-force limits by several orders of magnitude. However, we show that for a generic light scalar, unrelated to the strong CP problem, present bounds from direct fifth- force searches are more stringent than those inferred from EDM limits, for the interaction ranges explored by fifth-force experiments. Thus, correlating observations in EDM and fifth-force experiments could help distinguish axions from more generic light scalar scenarios.

Full Text Available This paper aims to study on the feasibility of micron size hole manufacturing using micro Electric Discharge Machining (Micro-EDM. Main and auxiliary unit of the micro-EDM machine tool and their functions are described in some detail. The technological and electrical parameters that are effective in Micro-EDM are stated explicitly. Geometry of the machined micro-holes and resolidified material around the hole entrance are observed. Several descriptive pictures, obtained by Scanning Electron Microscope (SEM are included to understand the phenomena. EDM is an important process in the field of micro machining. However, a number of issues remain to be solved in order to successfully implement it an industrial environment. This study investigates the optimization of machining parameters for machining in micro EDM. Here, the overcut and the Metal Removal Rate (MRR and Tool wear ratio are targeted. The study focuses on a specific combination of electrode and work piece material and proposes a typical method for micro EDM process optimization. The cutting of the Inconel 718 using Micro EDM with a brass electrode by using Taguchi methodology has been reported. The Taguchi method is used to formulate the experiment layout, to analyze the effect of each parameter on the machining characteristics and to predict the optimal choice for each EDM parameters like Discharge current, Pulse on time, Pulse off time. It found that these parameters have a significant influence on the machining characteristics such as Metal Removal Rate (MRR, Overcut and Tool wear ratio.

The first recorded experiments describing the phenomena made popular by Newton's cradle appear to be those conducted by Edme Mariotte around 1670. He was quoted in Newton's "Principia," along with Wren, Wallis, and Huygens, as having conducted pioneering experiments on the collisions of pendulum balls. Each of these authors concluded that momentum…

A discovery of a permanent electric dipole moment of the electron (eEDM) would provide crucial information about the nature of T-violation and imply new sources of CP-violation beyond the Standard Model. While the leading experimental technique used to measure EDM is based on the nuclear magnetic resonance, we are pursuing research that would improve the present experimental limit of the eEDM using a new technique in solid-state systems at low temperatures. The experiment uses a paramagnetic insulator Gadolinium Gallium Garnet with a large magnetic response. The presence of the eEDM leads to a finite magnetization when the garnet sample is subjected to a strong electric field. The resulting magnetization can be measured using the Superconducting Quantum Interference Device (SQUID) as a sensitive magnetometer. In this talk, we will discuss the progress to control the systematic effects and improve the sensitivity. The major efforts include the design and implementation of a 24-bit data acquisition system with ultra-low level of channel crosstalk, and the control of the high voltage drift from the supply. With these considerable progresses, we report our first background-free experimental limit of the eEDM on the order of 10-24 e.cm .

A non-zero Electric Dipole Moment (EDM) of an elementary particle means the violation of the time-reversal symmetry and the CP violation assuming the CPT invariance. The super symmetry model (SUSY) predicts the EDM large enough to be observed with the modern experimental technique. In alkali atoms, an electronEDM results in an atomic EDM enhanced by the factor ˜Z^3?^2, especially francium (Fr) has the largest enhancement factor ˜ 1150. However Fr is a radioactive atom with a finite life time, we need to establish the technique to produce over 10^7 atoms/sec, cool and collect them quickly into laser trap apparatus as a cold dense cloud of neutral atoms to measure the EDM accurately. Thermal Ionizer produce the high intensity Fr ion using a fusion reaction of ^18O+^197Au->^210Fr+5n with a primary beam energy E^18O ˜100 MeV. This ionizer consists of the Au target surrounded by the high temperature oven to stop the ion spreading out. Thanks to the small extraction electrode hole, we can realize the small emittance Fr beam, and the high transmission efficiency. We have achieved to produce over ˜10^4 atom/sec, and transport them along 3 meter without losing the Fr ions.

In this paper, the performances and requirements of conventional Electrical Discharge Machining (EDM) and micro EDM technologies are described in order to explore obstacles to the introduction of micro EDM technologies into industrial environment. Special attention is given to machine tool accuracy, machining accuracy, electric pulses, pulse generators and environmental requirements. EDM has been widely used in toolmaking industry to produce dies, moulds and other tools for mass production. It was also found suitable for machining meso and micro structures, since its removal mechanism induces very low machining forces. In particular, a new technology called micro EDM milling, employing milling like strategies, was developed to enable the machining of 3D micro features. Keyword: Micro EDM milling,Microtechnologies,Pulse generator,Accuracy,Die-sinking EDM

The relations between matrix elements of different P- and T-odd weak interactions are derived. We demonstrate that similar relations hold for parity nonconserving (PNC) transition amplitudes and electron electric dipole moments (EDM) of atoms and molecules. This allows to express P- and T-odd effects in many-electron systems caused by different symmetry-breaking mechanisms via each other using simple analytical formulas. We use these relations for the interpretation of the anapole moment measurements in cesium and thallium and for the analysis of the relative contributions of the scalar-pseudoscalar CP-odd weak interaction and electronEDM to the EDM of Cs, Tl, Fr and other atoms and many polar molecules (YbF, PbO, ThO, etc.). Model-independent limits on electronEDM and the parameter of the scalar-pseudoscalar CP-odd interaction are found from the analysis of the EDM measurements for Tl and YbF.

In 1968, Shapiro published the suggestion that one could search for an electron dipole moment (EDM) by applying a strong electric field to a substance that has an unpaired electron spin; at low temperature, the EDM interaction would lead to a net sample magnetization that can be detected with a superconducting quantum interference device (SQUID) magnetometer. One experimental EDMsearch based on this technique was published, and for a number of reasons including high sample conductivity, high operating temperature, and limited SQUID technology, the result was not particularly sensitive compared to other experiments in the late 1970s. Advances in SQUID and conventional magnetometery led us to reconsider this type of experiment, which can be extended to searches and tests other than EDMs (e.g., test of Lorentz invariance). In addition, the complementary measurement of an EDM-induced sample electric polarization due to application of a magnetic field to a paramagnetic sample might be effective using modern ultrasensitive charge measurement techniques. A possible paramagnetic material is Gd-substituted yttrium iron garnet which has very low conductivity and a net enhancement (atomic enhancement times crystal screening) of order unity. Use of a reasonable volume (hundreds of cm3) sample of this material at 50 mK and 10 kV/cm might yield an EDM sensitivity of 10-32 e cm or better, a factor of 105 improvement over current experimental limits

The electric dipole moment of the electron (eEDM) is a signature of CP-violating physics beyond the standard model. We describe an ongoing experiment to measure or set improved limits to the eEDM, using a cold beam of thorium monoxide (ThO) molecules. The metastable H {sup 3}{Delta}{sub 1} state in ThO has important advantages for such an experiment. We argue that the statistical uncertainty of an eEDM measurement could be improved by as much as three orders of magnitude compared to the current experimental limit, in a first-generation apparatus using a cold ThO beam. We describe our measurements of the H state lifetime and the production of ThO molecules in a beam, which provide crucial data for the eEDM sensitivity estimate. ThO also has ideal properties for the rejection of a number of known systematic errors; these properties and their implications are described.

Abstract Background Most electronicsearch efforts directed at identifying primary studies for inclusion in systematic reviews rely on the optimal Boolean search features of search interfaces such as DIALOG® and Ovid™. Our objective is to test the ability of an Ultraseek® search engine to rank MEDLINE® records of the included studies of Cochrane reviews within the top half of all the records retrieved by the Boolean MEDLINE search used by...

The nEDM experiment, currently being developed to be constructed at the Fundamental Neutron Physics Beamline at Oak Ridge National Laboratory, will search for the neutron electric dipole moment (EDM) with a sensitivity roughly two orders of magnitude better than the current limit. In neutron EDMsearches, the signature of an EDM appears as a shift in the neutron spin precession frequency upon an application of an electric field for neutrons precessing in a weak magnetic field. In the nEDM experiment, the neutron precession will be measured with respect to that of polarized ^3He atoms, which will occupy the same volume as the neutrons and act as a co-magnetometer. Liquid helium (LHe) scintillation from the spin dependent ^3He(n,p)t reaction will be used to determine the n-^3He precession frequency difference. The existing data on LHe scintillation in an electric field do not cover the expected electric field and operating temperature of the nEDM experiment. We measured the LHe scintillation yield dependence on the electric field strength up to ˜45 kV/cm in the temperature range of 0.2-1.1K at the saturated vapor pressure. In this talk, the results of the measurements will be presented, along with their implication for the nEDM experiment.

Since the 1950's people have been searching for electric dipole moments (EDMs) of fundamental particles. This is a very promising approach to find yet unknown manifestations of broken underlying symmetries in the early Universe. Although these experiments are among the most precise in physics, no EDM has been observed so far. In this talk a next generation approach with a sensitivity of <5.10{sup -28} ecm (3{sigma}) for the neutron EDM based at the FRM-II neutron source is presented. Ramsey's method of separated oscillatory fields is applied to trapped ultra-cold neutrons (UCNs) in vacuum. For the investigation of systematic effects a sophisticated strategy of various means to control ambient parameters on an unprecedented level of accuracy is currently being set up. The construction is planned to be finished by end of 2013, followed by the first measurements with UCNs in 2014. An overview of the overall strategy, main systems for magnetic field control and magnetometry, as well as the current status of the ongoing implementation on site is shown.

Since the 1950's people have been searching for electric dipole moments (EDMs) of fundamental particles. This is a very promising approach to find yet unknown manifestations of broken underlying symmetries in the early Universe. Although these experiments are among the most precise in physics, no EDM has been observed so far. In this talk a next generation approach with a sensitivity of -28 ecm (3?) for the neutron EDM based at the FRM-II neutron source is presented. Ramsey's method of separated oscillatory fields is applied to trapped ultra-cold neutrons (UCNs) in vacuum. For the investigation of systematic effects a sophisticated strategy of various means to control ambient parameters on an unprecedented level of accuracy is currently being set up. The construction is planned to be finished by end of 2013, followed by the first measurements with UCNs in 2014. An overview of the overall strategy, main systems for magnetic field control and magnetometry, as well as the current status of the ongoing implementation on site is shown.

Full Text Available This project research undertakes the assessment of powder added electrical discharge machining (PMDM with focus on effect of additive powders and circulation systems. In PMEDM process, powder can be mixed with dielectric fluid either in the main EDM tank or in a separate tank in order to improve EDM machining performance. Different designs of powder mixed EDM circulating systems such as closed and opened systems with different sizes of tank are described in literature. Various devices such as stirrer, circulating pump etc. are placed in the tank in order to ensure the uniformity of powder mixed dielectric. Each design has its advantages and disadvantages and it might affect the EDM output results. Therefore, there is a need to review the PMEDM with respect to additive powders and circulation systems in order to identify the gap and propose an alternative for improving process.

Micro Electrical Discharge Machining (micro-EDM) is a plasma-assisted process for the manufacturing of micro-components in high-hardness conductive materials. The removal of material is the result of a sum of dc discharges, produced within a point to plane system of electrodes immersed in a dielectric fluid, whose electric disruption with the development of plasma-currents can be induced by imposing a threshold voltage. To better understand the interaction between the micro-plasma and the material, we have designed and build an experimental setup for the production of single-discharges, characterized by a constant voltage-current operation point. The device allows the ignition of resistive plasmas in air/water at different pulse-times (˜100--3200 ?s), currents (˜1-20 A for ˜75-250 V), polarities and gap-sizes (˜0,5-25 ?m), and the changes in these work conditions can be correlated to the type and size of the craters produced. The micro-plasma electron density ne is measured using the Stark broadening of the H? atomic line. First results give ne ˜ 10^16 -- 10^17 cm^3, in agreement with estimates obtained from an electrical circuit model of the discharge.

This Software Configuration Management Plan (SCMP) provides the requirements for control of the Search Hanford Accessible Reports Electronically (SHARE) software and documentation. The SHARE system consists of the TOPIC Text Search and Retrieval software and the programs necessary to extract information from other sources to be placed in SHARE.

A search for excited electrons is performed using the full $e^{\\pm}p$ data sample collected by the H1 experiment at HERA, corresponding to a total luminosity of 475 pb$^{-1}$. The electroweak decays of excited electrons ${e}^{*}\\to{e}{\\gamma}$, ${e}^{*}\\to{e}Z$ and ${e}^{*}{\\to}\

This paper reports a search for excited electrons at the HERA electron-proton collider. In a sample corresponding to an integrated luminosity of 26 nb-1, no evidence was found for any resonant state decaying into e-?, ?W- or e-Z0. Limits on the coupling strength of an excited electron have been determined for masses between 45 and 225 GeV. This study also reports the observation of the wide-angle e? Compton scattering process. (orig.)

Full Text Available Abstract Background Most electronicsearch efforts directed at identifying primary studies for inclusion in systematic reviews rely on the optimal Boolean search features of search interfaces such as DIALOG® and Ovid™. Our objective is to test the ability of an Ultraseek® search engine to rank MEDLINE® records of the included studies of Cochrane reviews within the top half of all the records retrieved by the Boolean MEDLINE search used by the reviewers. Methods Collections were created using the MEDLINE bibliographic records of included and excluded studies listed in the review and all records retrieved by the MEDLINE search. Records were converted to individual HTML files. Collections of records were indexed and searched through a statistical search engine, Ultraseek, using review-specific search terms. Our data sources, systematic reviews published in the Cochrane library, were included if they reported using at least one phase of the Cochrane Highly Sensitive Search Strategy (HSSS, provided citations for both included and excluded studies and conducted a meta-analysis using a binary outcome measure. Reviews were selected if they yielded between 1000–6000 records when the MEDLINE search strategy was replicated. Results Nine Cochrane reviews were included. Included studies within the Cochrane reviews were found within the first 500 retrieved studies more often than would be expected by chance. Across all reviews, recall of included studies into the top 500 was 0.70. There was no statistically significant difference in ranking when comparing included studies with just the subset of excluded studies listed as excluded in the published review. Conclusion The relevance ranking provided by the search engine was better than expected by chance and shows promise for the preliminary evaluation of large results from Boolean searches. A statistical search engine does not appear to be able to make fine discriminations concerning the relevance of bibliographic records that have been pre-screened by systematic reviewers.

A search for ?? ? ?e and anti ?? ? anti ?e oscillations has been carried out with the CHARM II detector exposed to the CERN wide band neutrino beam. The data were collected over five years, alternating beams mainly composed of muon-neutrinos and muon-antineutrinos. The number of interactions of ?e and anti ?e observed is comparable with the number of events expected from flux calculations. For large squared mass differences the upper limits obtained on the mixing angle are sin22? -3 for ?? oscillating to ?e and sin22? -3 for anti ?? to anti ?e, at the 90% confidence level. Combining neutrino and antineutrino data the upper limit is 5.6 . 10-3. (orig.)

We report results of an experimental search for the intrinsic Electric Dipole Moment (EDM) of the electron using a solid-state technique. The experiment employs a paramagnetic, insulating gadolinium gallium garnet (GGG) that has a large magnetic response at low temperatures. The presence of the eEDM would lead to a small but non-zero magnetization as the GGG sample is subject to a strong electric field. We search for the resulting Stark-induced magnetization with a sensitive magnetometer. Recent progress on the suppression of several sources of background allows the experiment to run free of spurious signals at the level of the statistical uncertainties. We report our first limit on the eEDM of $(-5.57 \\pm 7.98 \\pm 0.12)\\times10^{-25}$e$\\cdot$cm with 5 days of data averaging.

A search for excited electrons is performed using the full e{sup {+-}}p data sample collected by the H1 experiment at HERA, corresponding to a total luminosity of 475 pb{sup -1}. The electroweak decays of excited electrons e{sup *} {yields}e{gamma}, e{sup *} {yields}eZ and e{sup *} {yields}{nu}W with subsequent hadronic or leptonic decays of the W and Z bosons are considered. No evidence for excited electron production is found. Mass dependent exclusion limits on e{sup *} production cross sections and on the ratio f/{lambda} of the coupling to the compositeness scale are derived within gauge mediated models. These limits extend the excluded region compared to previous excited electronsearches. The e{sup *} production via contact interactions is also addressed for the first time in ep collisions. (orig.)

The nEDM experiment is a new search for the electric dipole moment (EDM) of the neutron with a sensitivity of 10-28 e-cm at the recently constructed Spallation Neutron Source (SNS). The measurement requires a static magnetic field surrounding two target cells that contain superfluid ^4He, polarized neutrons and polarized ^3He atoms. The latter are used as a co-magnetometer and ultracold neutron spin precession frequency analyzer. The applied static magnetic field, B0, is chosen to be about 10 mG resulting in a precession of the magnetic moments for both neutrons and ^3He nuclei of ˜30 Hz. To maintain the polarization of the neutrons and ^3He atoms, the magnetic field should be very uniform with gradients of the order of 0.1 ?G/cm averaged over each cell volume. A separate requirement on the volume-averaged magnetic field gradient in the direction of B0 of less than 0.01 ?G/cm is necessary to minimize false EDM signals. In addition, to reduce the influence of ambient external fields an overall magnetic shielding factor of ˜10^5 is required. We present finite-element calculation results for the complete nEDM static magnetic field configuration including magnetic field gradients and ^3He relaxation rates.

High-voltage sparks in the lab unexpectedly emit x-rays with energies up to several hundred keV. These x-rays have been observed repeatedly and can only be produced by bremsstrahlung, impling the presence of a population of energetic electrons. Such energetic electron and x-ray production may be important for the physics of streamers, spark discharges, and lightning, and has been suggested as directly related to the production of terrestrial gamma-ray flashes. We present the results of the first direct search for energetic electrons produced by a lab spark. Small electrically-isolated scintillators are placed at various locations near the spark gap of a 2 MV Marx generator and the resulting signals are recorded. We present results on the spatial, temporal, and statistical variability of signals produced by energetic electrons and compare our results to predictions of energetic electron production from the literature.

An experiment to measure the permanent electric dipole moment (EDM) of ^223Rn is under development at TRIUMF. The EDM of ^223Rn is expected to be enhanced by a factor of several hundred relative to ^199Hg due to effects of octupole deformation. In the first runs, the ^223Rn will be polarized by spin-exchange with laser polarized Rb and the precession frequency in combined magnetic fields will be measured using gamma-ray anisotropies detected in the large solid angle TIGRESS array of HPGe detectors. In preparation, polarization and relaxation of radon isotopes by spin exchange with laser optically pumped rubidium have been studied over the range 130^oC to 220^oC. The generation of a greater rubidium polarization in the radon spin-exchange optical pumping cells using a narrow-band diode laser is under investigation. Other preparations and the time frame for the measurements will be presented.

The latest-generation neutron electric dipole moment (EDM) experiment has been collecting data at the ILL since 1996. It uses a 'cohabiting' atomic-mercury magnetometer to measure and compensate for the magnetic field fluctuations that were the principal source of systematic errors in previous experiments. The first results, which are soon to be published, essentially verify the existing limit on the dipole moment d sub n; however, this new measurement is clearly limited by statistical rather than systematic uncertainties.

Full Text Available Background This paper presents a novel approach to searchingelectronic medical records that is based on concept matching rather than keyword matching. Aims The concept-based approach is intended to overcome specific challenges we identified in searching medical records. Method Queries and documents were transformed from their term-based originals into medical concepts as defined by the SNOMED-CT ontology. Results Evaluation on a real-world collection of medical records showed our concept-based approach outperformed a keyword baseline by 25% in Mean Average Precision. Conclusion The concept-based approach provides a framework for further development of inference based search systems for dealing with medical data.

Optimization of multi criteria problems is a great need of producers to product precision parts with low costs. Many methods such as Taguchi and Response Surface Methodology have been employed for optimization of EDM process. However there are few researches involve the optimization of multi-response problem in EDM process. The attempt of this paper is to optimize multiple performance characteristics of EDM process using Grey relational analysis based on Taguchi orthogonal array. The r...

We study the potential of $\\gamma \\gamma$ option of future high energy linear $e^{+}e^{-}$ colliders to search for excited electrons with spin-1/2. We calculate single production cross sections, give the angular distributions and $f-m^*$ contour plots for $\\sqrt{s}=0.5$ TeV and $\\sqrt{s}=3$ TeV both using the standard (tree level) couplings and anomal couplings.

Full Text Available We plan to measure the permanent electric dipole moment (EDM of the electron, which has the sensitivity to the CP violation in theories beyond the standard model by using the laser-cooled francium (Fr atom. This paper reports the present status of the EDM measurement system. A high voltage application system was constructed in order to produce the strong electric field (100 kV/cm needed for the experiment. After conditioning, the leakage current was 10 pA when a high voltage of 43 kV was applied. Also, a drift of an environmental field was measured at the planned location of the Fr-EDM experiment. The drift is suppressed at present down to the level of 10 pT by installing a 4-layermagnetic shield. Improvements are still needed to reach the required field stability of 1 fT.

A proof-of-principle electron electric-dipole-moment (e-EDM) experiment using slow cesium atoms, nulled magnetic fields, and electric-field quantization has been performed. With the ambient magnetic fields seen by the atoms reduced to less than 200 pT, an electric field of 6 MV/m lifts the degeneracy between states of unequal |mF| and, along with the low (?3 m/s) velocity, suppresses the systematic effect from the motional magnetic field. The low velocity and small residual magnetic field have made it possible to induce transitions between states and to perform state preparation, analysis, and detection in regions free of applied static magnetic and electric fields. This experiment demonstrates techniques that may be used to improve the e-EDM limit by two orders of magnitude, but it is not in itself a sensitive e-EDMsearch, mostly due to limitations of the laser system

A proof-of-principle electron electric-dipole-moment (e-EDM) experiment using slow cesium atoms, nulled magnetic fields, and electric-field quantization has been performed. With the ambient magnetic fields seen by the atoms reduced to less than 200pT , an electric field of 6MV/m lifts the degeneracy between states of unequal ?mF? and, along with the low (?3m/s) velocity, suppresses the systematic effect from the motional magnetic field. The low velocity and small residual magnetic field have made it possible to induce transitions between states and to perform state preparation, analysis, and detection in regions free of applied static magnetic and electric fields. This experiment demonstrates techniques that may be used to improve the e-EDM limit by two orders of magnitude, but it is not in itself a sensitive e-EDMsearch, mostly due to limitations of the laser system.

A proof-of-principle electron electric dipole moment (e-EDM) experiment using slow cesium atoms, nulled magnetic fields, and electric field quantization has been performed. With the ambient magnetic fields seen by the atoms reduced to less than 200 pT, an electric field of 6 MV/m lifts the degeneracy between states of unequal mF and, along with the low (approximately 3 m/s) velocity, suppresses the systematic effect from the motional magnetic field. The low velocity and small residual magnetic field have made it possible to induce transitions between states and to perform state preparation, analysis, and detection in regions free of applied static magnetic and electric fields. This experiment demonstrates techniques that may be used to improve the e-EDM limit by two orders of magnitude, but it is not in itself a sensitive e-EDMsearch, mostly due to limitations of the laser system.

An experimental search for selectrons, the supersymmetric partner of the electron, has been performed at the PEP storage ring at SLAC using the Mark II detector. The experimental search done was based upon hypothetical reaction in e+e- interactions at PEP center of mass energies of 29 GeV. In this reaction the selectrons, e, are assumed produced by the interaction of one of initial state electrons with a photon radiated from the other initial state electron. This latter electron is assumed to continue down the beam pipe undetected. The photon and electron then produce a selectron and a photino, ?, in the supersymmetric analog of Compton scattering. The photino is assumed to be the lightest supersymmetric particle, and as such, does not interact in the detector, thereby escaping detection very much like a neutrino. The selectron is assumed to immediately decay into an electron and photino. This electron is produced with large p perpendicular with respect to the beam pipe, since it must balance the transverse momentum carried off by the photinos. Thus, the experimental signature of the process is a single electron in the detector with a large unbalanced tranverse momentum. No events of this type were observed in the original search of 123 pb-1 of data, resulting in a cross section limit of less than 2.4 x 10-2 pb (at the 95% CL) within the detector acceptance. This cross section upper limit applies to any process which produces anomalous single electron events with missing transverse momentum. When interpreted as a supersymmetry search it results in a lower selectron mass limit of 22.2 GeV/c2 for the case of massless photinos. Limits for non-zero mass photinos have been calculated. 87 refs., 67 figs., 17 tabs

The phenomena occurring between the electrodes in electric discharge machining when manufacturing features on the micro-metre scale (µ-EDM) is not fully understood. Poor quantitative knowledge of the sources of variability affecting this process hinders the identification of its natural tolerance limits. Moreover, improvements in measuring systems contribute to the acquisition of new information that often conflicts with existent theoretical models of this process. The prime objective of this paper is to advance the experimental knowledge of µ-EDM by providing a measurement framework for the electrical discharges. The effects of the electrodes metallic materials (Ag, Ni, Ti, W) on the electrical measurements defined in the proposed framework are analysed. Linear mixed-effects models are fitted to the experimental data using the restricted maximum likelihood method (REML). The main conclusion drawn is that the discharge current and voltage as defined and measured in this framework do significantly depend on the electrode material even when keeping all the other machining conditions unchanged

The phenomena occurring between the electrodes in electric discharge machining when manufacturing features on the micro-metre scale (µ-EDM) is not fully understood. Poor quantitative knowledge of the sources of variability affecting this process hinders the identification of its natural tolerance limits. Moreover, improvements in measuring systems contribute to the acquisition of new information that often conflicts with existent theoretical models of this process. The prime objective of this paper is to advance the experimental knowledge of µ-EDM by providing a measurement framework for the electrical discharges. The effects of the electrodes metallic materials (Ag, Ni, Ti, W) on the electrical measurements defined in the proposed framework are analysed. Linear mixed-effects models are fitted to the experimental data using the restricted maximum likelihood method (REML). The main conclusion drawn is that the discharge current and voltage as defined and measured in this framework do significantly depend on the electrode material even when keeping all the other machining conditions unchanged. This investigation was carried out while the authors were at the Manufacturing Engineering Centre of Cardiff University.

We discuss slepton mass matrices in the $S_4$ flavor model with SUSY $SU(5)$ GUT. By considering the gravity mediation within the framework of supergravity theory, we estimate the SUSY breaking terms in the slepton mass matrices, which contribute to the $\\mu \\rightarrow e + \\gamma$ decay. We obtain a lower bound for the ratio of $\\mu\\rightarrow e\\gamma$ as $10^{-13}$ if $m_{\\text{SUSY}}$ and $m_{1/2}$ are below $500$GeV. The off diagonal terms of slepton mass matrices also contribute to EDM of leptons. The predicted electronEDM is around $10^{-29}-10^{-28}$cm. Our predictions are expected to be tested in the near future experiment.

Developments are in progress aiming at the search for a permanent Electric Dipole Moment (EDM) in 129Xe atom using a low-frequency nuclear spin maser. In the EDM experiment, drifts in the applied static magnetic field in a long time scale are the dominating source of errors in frequency determination. The stability of the applied field and its monitoring by use of a high sensitivity magnetometer are thus the indispensable part of the EDM experiment. We are developing a magnetometer based on the Nonlinear Magneto-Optical Rotation (NMOR) effect in Rb atom. The sharp response to the magnetic field in this apparatus relies on a long relaxation time of the atomic spin alignment induced by linearly polarized laser light, and thus the suppression of the atomic decoherence should be essential for its sensitivity. Coating the inner walls of the cell with an antirelaxation layer, introducing a buffer gas in the cell and cancelling the transverse magnetic field should be effective in preventing atoms from depolarization. We obtained several NMOR spectra for Rb in cylindrical cells in such attempts. Up to now a sensitivity of ?B=1.5 × 10-5 G has been attained in the present setup.

Developments are in progress aiming at the search for a permanent Electric Dipole Moment (EDM) in 129Xe atom using a low-frequency nuclear spin maser. In the EDM experiment, drifts in the applied static magnetic field in a long time scale are the dominating source of errors in frequency determination. The stability of the applied field and its monitoring by use of a high sensitivity magnetometer are thus the indispensable part of the EDM experiment. We are developing a magnetometer based on the Nonlinear Magneto-Optical Rotation (NMOR) effect in Rb atom. The sharp response to the magnetic field in this apparatus relies on a long relaxation time of the atomic spin alignment induced by linearly polarized laser light, and thus the suppression of the atomic decoherence should be essential for its sensitivity. Coating the inner walls of the cell with an antirelaxation layer, introducing a buffer gas in the cell and cancelling the transverse magnetic field should be effective in preventing atoms from depolarization. We obtained several NMOR spectra for Rb in cylindrical cells in such attempts. Up to now a sensitivity of ?B=1.5 x 10-5 G has been attained in the present setup.

The search for an electric dipole moment of the neutron tests physics beyond the Standard Model such as new sources of CP-violation and Supersymmetry. The nEDM experiment aims to improve the sensitivity on the current limit of the electric dipole moment of the neutron to EDM when an electric field is applied parallel and antiparallel to a magnetic field across the neutron storage cell. A dominant parameter in terms of reducing the statistical uncertainty of this measurement is the strength of the applied electric field. An experiment to measure if superfluid He-II can sustain up to 50 kV/cm for a volume and electrode spacings comparable to the nEDM experiment has been constructed at Los Alamos National Laboratory. It consists in a large-area parallel plate capacitor immersed in a 200 liter central volume inside a suitable cryostat that in turn is connected to a dilution refrigerator unit. A description of test runs and the status of the experiment is presented.

Discussion of online consumer behavior focuses on the development of a conceptual model and a set of propositions to explain the main factors influencing online price search. Integrates the psychological search literature into the context of online searching by incorporating ability and cost to search for information into perceived search…

We have searched for the nuclear excitation by electronic transition (NEET) of the isomeric level at 76 eV in 235U in a plasma induced by a YAG laser with an energy of 1 Joule and a full width at half maximum time distribution of 5 ns, operating at an intensity of 1013 W cm-2. We present a thorough description of the experimental conditions and analysis of our data. In this experimental situation we do not detect any excitation of the isomeric level, a result that is at variance with a previously reported one. An upper limit of 6x10-6 per atom and per second averaged over the laser-pulse width has been set on the nuclear excitation rate. This value is compared with results obtained in previous experimental and theoretical works

Limits on the lepton-flavor-violating reactions ?-+Z?e-+Z and ?-+Z?e++(Z-2), muon-electron and muon-positron conversion, have been obtained from a search performed at TRIUMF using a time-projection chamber. Upper limits (90% C.L.) for the branching ratios compared to ordinary muon capture for a titanium target are R: (Ti) = ?(?-Ti?e-Ti)/?(?-Ti capture)-Ti?e+Ca*)/?(?-Ti capture)

A variety of Dark Matter particle candidates have been hypothesized by physics Beyond the Standard Model (BSM) in the very light (10-6 - 10-3 eV) range. In the past decade several international groups have conducted laboratory experiments designed to either produce such particles or extend the boundaries in parameter space. The LIght Pseudo-scalar and Scalar Search (LIPSS) Collaboration, using the 'Light Shining through a Wall' (LSW) technique, passes the high average power photon beam from Jefferson Lab's Free-Electron Laser through a magnetic field upstream from a mirror and optical beam dump. Light Neutral Bosons (LNBs), generated by coupling of photons with the magnetic field, pass through the mirror ('the Wall') into an identical magnetic field where they revert to detectable photons by the same coupling process. While no evidence of LNBs was evident, new scalar coupling boundaries were established. New constraints were also determined for hypothetical para-photons and for millicharged fermions. We will describe our experimental setup and results for LNBs, para-photons, and milli-charged fermions. Plans for chameleon particle searches are underway.

I want to discuss the role of neutrino-electron scattering in the search for physics beyond the standard model. The standard model makes specific predictions about the nature of the neutrinos which participate in such processes and about the interactions responsible for them. The process upon which I shall concentrate is elastic scattering, but I shall pay some attention to inelastic processes in which the target electron is itself transformed into a heavier charged lepton, in other words the inverse of the decay of the heavier lepton. In the case of elastic scattering we are mainly looking at neutral-currents and we can ask a series of simple questions: Does the interaction conserve lepton flavor. Does it fit the prescriptions of the standard model. Are the neutrinos Majorana or Dirac particles. In the case of inverse muon and tau decays we are looking at charge-currents, and we want to pin down the identity of the neutrinos emitted in the decay of these charged leptons as well as to set bounds on non-(V-A) components of the interaction. In order to discuss these topics, it is useful to review the general properties of the scattering process, especially the kinematics and the general form of the differential cross-section. Kinematics are important because they prevent us from searching for some processes and effects which we would like to detect. The differential cross-section, if measured with sufficient care, may tell us something about the presence of non-standard terms in the interaction and even about the nature of the neutrino. The detailed outline of the talk is: identity of the final state neutrino; kinematics; differential cross-sections; oscillations and universality; a test for Dirac neutrinos; inverse muon decay; and the standard model and radiative corrections. 22 ref., 2 tabs.

Recently an improved limits on the electron electric dipole moment, \\eEDM, and dimensionless constant, $k_{T,P}$, characterizing the strength of the T,P-odd pseudoscalar$-$scalar electron$-$nucleus neutral current interaction in the $H^3\\Delta_1$ state of ThO molecule were obtained by ACME collaboration [Science 343, 269 (2014)]. The interpretation of the experiment in terms of fundamental quantities \\eEDM\\ and $k_{T,P}$ is based on the results of theoretical study of appropriate ThO characteristics, the effective electric field acting on electron, \\Eeff, and a parameter of the T,P-odd pseudoscalar$-$scalar interaction, $W_{T,P}$, given in [J.Chem.Phys.\\ 139, 221103 (2013)] by St.Petersburg group. To reduce the uncertainties of the given limits we report improved calculations of the molecular state$-$specific quantities \\Eeff, 81.5~GV/cm, and $W_{T,P}$, 112~kHz, with the uncertainty within 7\\% of the magnitudes. Thus, the values recommended to use for the upper limits of the quantities are 75.8~GV/cm and 104~...

In this research a multi-point micro punch and die system was developed. The process of electric discharge machining (EDM) was used to produce both the punch and die. The punches were machined from a 5 mm diameter tungsten and a 10 mm diameter tool steel round rods by wire electric discharge machining (WEDM), using a 200 µm diameter wire electrode. The die holes were made using the punch as the electrode. The EDM process of the holes was carried out on a newly developed desktop EDM machine. The punch and die placed on a micro-die set and then on a micro press were used to produce micro-holes using an automatic control system developed for this process. Experiments to produce 50 µm to 67 µm square micro-holes on 50 µm thick aluminum, 30 µm thick copper and 20 µm thick stainless steel foils were conducted. The capabilities of multi-point punching using the tungsten punch and a tool steel punch were examined and tungsten was chosen as the material of choice for making the punch tool. A scanning electron microscope confirmed that the holes produced are clean, and the sheared surfaces smooth. The punch tool showed no signs of deformation or cracks even after repeated punching.

This paper presents an analysis of the positron capture by a neutron reaction, which is just the inverse of the well-known neutrino capture by a proton reaction. The effect of the QED radiative corrections is investigated. In particular, the analysis considers the effects of treating the neutron as a composite object that can have an electric dipole moment (nEDM). For the case of unpolarized hadrons the effects of a nEDM appear to vanish.

The increasing demand for mechanical micro components has enhanced the development of numerous production technologies, like micro-EDM. Micro-EDM is able to guarantee the latest market requirements both in terms of miniaturization capabilities and quality of the features obtained. With this production technique it is possible to fabricate several types of features such as, small 3D milled features and HAR (High Aspect Ratio) micro holes. One of the main concerns in micro machining, and most o...

The fabrication of high aspect ratio microstructures is very challenging, especially when the work piece material is hard to machine. Electro Discharge Machining (EDM) offers a contact- and nearly force free way of micromachining and is therefore an appropriate means to producing microstructures. One key obstacle for a precise machining by micro-EDM is the tool wear. When ED-machining microstructures process speed, stability and thus tool wear are related to the aspect ratio of the structures...

This paper presents a novel process using micro-electro-discharge- machining (micro-EDM) combined with ultrasonic vibration by a helical micro-tool electrode to drill and finish micro-holes. During the machining processes, a micro-tool is directly fabricated by wire electro-discharge grinding (WEDG) using micro-EDM combined with various methods for machining the micro-hole and by ultrasonic vibration to finish the hole wall. In this work, circular micro-holes are machined in a high nickel alloy by cylindrical and helical electrodes. Using a helical micro-tool electrode for micro-EDM combined with ultrasonic vibration (HE-MEDM-UV) can substantially reduce the EDM gap, taper and machining time for deep micro-hole drilling. In addition, using a helical micro-tool with micro ultrasonic vibration finishing (HE-MUVF), good surface quality and less taper of the hole wall can be obtained by applying a suitable electrode step variation, rotational speed and ultrasonic amplitude with a machining time of approximately 25 min. According to scanning electron microscopy (SEM) micrographs and atomic force microscopy (AFM) measurement, HE-MUVF can indeed improve the surface roughness from 1.345 µm Rmax before finishing to 0.58 µm Rmax after HE-MUVF. This result demonstrates that using HE-MEDM-UV combined with MUVF can yield micro-holes of precise shape and smooth surface.

Unipolar induction (UI) is a fundamental physical process, which occurs when a conducting body transverses a magnetic field. It has been suggested that UI is operating in RX J0806+15 and RX J1914+24, which are believed to be ultra-compact binaries with orbital periods of 5.4 min and 9.6 min respectively. The UI model predicts that those two sources may be electron cyclotron maser sources at radio wavelengths. Other systems in which UI has been predicted to occur are short period extra-solar terrestrial planets with conducting cores. If UI is present, circularly polarised radio emission is predicted to be emitted. We have searched for this predicted radio emission from short period binaries using the VLA and ATCA. In one epoch we find evidence for a radio source, coincident in position with the optical position of RX J0806+15. Although we cannot completely exclude that this is a chance alignment between the position of RX J0806+15 and an artifact in the data reduction process, the fact that it was detected at ...

This paper presents an overview of possibilities and procedures for the delivery of the results of an online search. Word processors can add headers and footers which explain the topic of the search, even highlight search terms. Desktop publishing programs can produce typeset-like output. Electronic mail permits almost immediate delivery of search results. Local databases can give your patron results that can be searched time and again (provided you have taken care of copyright restrictions), give you a means for producing printed indexes of searches. Beyond lie personal information managers, hard disk organizers, and other new products.

This thesis presents experimental results from the ASP detector which took data on e+e- interactions in the PEP storage ring at SLAC. Its design was particularly suitable for searching for production of supersymmetric particles. The motivations for and phenomenology of Supersymmetry are discussed. In particular, the production of a single supersymmetric electron (''selectron'', e) in combination with a supersymmetric photon (''photino'', ?) would result in events in which a single electron and no other particles are observed in the detector at an e+e- collider such as PEP, provided the masses of these particles are not too large. Such events would also result from the production of a single supersymmetric W-boson (''wino'', W) in combination with a supersymmetric neutrino (''sneutrino'', ?). These processes make it possible to search for electrons and winos with masses greater than the beam energy. Observation of these unusual events would distinctly indicate the production of new particles. The ASP detector was designed to be hermetic and to provide efficient event reconstruction for low multiplicity events. The detector is described and its performance is evaluated; it is found to be well-suited to this study. The data sample collected with the detector was thoroughly analyzed for evidence of single-electron events. The various possible background processes are considered and Monte Carlo calculations of the distributions from single selectron and single wino production are presented. Using this information an efficient off-line event selection process was developed, and it is described in detail. 82 refs., 41 figs., 4 tabs

Full Text Available SciELO Chile | Language: English Abstract in english In this paper, on the basis of the topological index EDm derived from ionicity index matrix, improved distance matrix and branching degree matrix, we proposed the new topological descriptor EDm' by introducing the bond angle into hidden hydrogen graph of molecules and using the geometric distance in [...] stead of the sum of bond length between two vertexes. The EDm describes the molecular structure more accurately, and realizes unique characterization to cis-trans isomers. The quantitative structure-property relationship (QSPR) models, with correlation coefficients (R) in the range of 0.984-1.000 for the boiling point (b.p.), the standard enthalpy of formation ( DfHm?), the molar refraction (Rm) and the molar volume (Vm) of some cis-trans isomers for alkenes, are subsequently developed by index EDm'. Moreover, the good stability and predictive ability of the models were demonstrated by LOO (leave-one-out) method and RSP (random sampling prediction) method, which further manifests the index EDm has high potential of wide applications in QSPR study.

Full Text Available In this paper, on the basis of the topological index EDm derived from ionicity index matrix, improved distance matrix and branching degree matrix, we proposed the new topological descriptor EDm' by introducing the bond angle into hidden hydrogen graph of molecules and using the geometric distance instead of the sum of bond length between two vertexes. The EDm describes the molecular structure more accurately, and realizes unique characterization to cis-trans isomers. The quantitative structure-property relationship (QSPR models, with correlation coefficients (R in the range of 0.984-1.000 for the boiling point (b.p., the standard enthalpy of formation ( DfHm?, the molar refraction (Rm and the molar volume (Vm of some cis-trans isomers for alkenes, are subsequently developed by index EDm'. Moreover, the good stability and predictive ability of the models were demonstrated by LOO (leave-one-out method and RSP (random sampling prediction method, which further manifests the index EDm has high potential of wide applications in QSPR study.

In this paper, with the use of deionized water, a finishing process of micro hole surfaces processed by micro electrical discharge machining (micro-EDM) is investigated. A micro hole is machined by micro-EDM using deionized water as a dielectric fluid. The inner surface of the hole is finished successfully via electrochemical dissolution in deionized water. The effects of finishing conditions such as the resistivity of deionized water, the voltage, the tool rotation and the finishing time on the surface quality and accuracy of the shape were investigated. After a finishing process using deionized water with a resistivity of 2 M? cm, a voltage of 80 V, a tool rotation of 1200 rpm and a finishing time of 6 min, the surface roughness was reduced considerably from 0.225 µm Ra after micro-EDM to 0.066 µm Ra.

In this paper, with the use of deionized water, a finishing process of micro hole surfaces processed by micro electrical discharge machining (micro-EDM) is investigated. A micro hole is machined by micro-EDM using deionized water as a dielectric fluid. The inner surface of the hole is finished successfully via electrochemical dissolution in deionized water. The effects of finishing conditions such as the resistivity of deionized water, the voltage, the tool rotation and the finishing time on the surface quality and accuracy of the shape were investigated. After a finishing process using deionized water with a resistivity of 2 M? cm, a voltage of 80 V, a tool rotation of 1200 rpm and a finishing time of 6 min, the surface roughness was reduced considerably from 0.225 µm Ra after micro-EDM to 0.066 µm Ra

The use of electrical discharge machining (EDM), or spark erosion as it is sometimes called, introduces hydrogen into maraging steel 250 such that brittle fracture surfaces result from embrittlement accelerated by slow-strain-rate tensile tests. Brittle fracture features indicate potential premature failure due to hydrogen embrittlement. Experimental control was provided by test specimens machined by abrasive waterjet, a machining technique that does not evolve hydrogen as a part of the machining process. Hydrogen concentration measurements indicate the hydrogen concentration of specimens fabricated by EDM is approximately 0.5 ppm, while that of specimens machined by abrasive waterjet is approximately 0.1 ppm. On the basis of constant-load tests, the time to failure of test specimens machined by EDM and loaded to 50% of the yield strength is estimated to be a minimum of 30 years.

Full Text Available Optimization of multi criteria problems is a great need of producers to product precision parts with low costs. Many methods such as Taguchi and Response Surface Methodology have been employed for optimization of EDM process. However there are few researches involve the optimization of multi-response problem in EDM process. The attempt of this paper is to optimize multiple performance characteristics of EDM process using Grey relational analysis based on Taguchi orthogonal array. The response table and response graph for each level of the machining parameters is obtained and optimal levels of machining parameters including pulse on time, discharge current, discharge voltage and duty factor are found. The multiple performance characteristics including material removal rate, electrode wear ratio and surface roughness is considered.

Three different microstructures--equiaxed, bi-modal and coarse lamellar--are prepared from Ti-6Al-4V alloy. Electric discharge machining (EDM) with a high peak current (29 A) is performed in order to impose surface roughness and modify the chemical composition of the surface. Detailed scanning electron microscopy (SEM) investigation revealed a martensitic surface layer and subsurface heat affected zone (HAZ). EDX measurements showed carbon enriched remnants of the EDM process on the material surface. Rotating bending fatigue tests are undertaken for EDM processed samples for all three microstructures and also for electropolished-benchmark-samples. The fatigue performance is found to be rather poor and not particularly dependent on microstructure. The bi-modal microstructure shows a slightly superior high cycle fatigue performance. This performance can be further improved by a suitable heat treatment to an endurance limit of 200 MPa. PMID:22098894

In the supersymmetric model with local gauged baryon and lepton numbers(BLMSSM), the CP-violating effects are considered to study the lepton electric dipole moment(EDM). The CP-violating phases in BLMSSM are more than those in the standard model(SM) and can give large contributions. The analysis of the EDMs for the leptons $e,\\mu, \\tau$ is shown in this work. It is in favour of exploring the source of CP violating and probing the physics beyond SM.

The objective of the literature search was to determine the required material properties and electron interaction parameters needed for modeling charge buildup and breakdown in insulators. A brief overview of the results of the literature search is given. A partial list of the references covered is included in a bibliography. Although inorganic insulators were also considered in the search, coverage is limited to the organics, primarily Kapton and Teflon.

The CMS Working Group for Engineering and Integration ( WOGEI) has been involved in the Engineering Data Management System ( EDMS) Task Force. This Task Force has started in 1995 with definition and selection procedure for an EDMS. The aim is to find out whether an EDMS is useful for CERN and the LHC experiments and which product is most suited. The CMS-WOGEI has proposed and carried out a pilot project with Matrix, the EDMS selected by the EDMS task force. In this technical note the pilot project is described and the experience gained with this is summarised.

Electron migration between and within proteins is one of the most prevalent forms of biological energy conversion processes. Electron transfer reactions take place between active centers such as transition metal ions or organic cofactors over considerable distances at fast rates and with remarkable specificity. The electron transfer is attained through weak electronic interaction between the active sites, so that considerable research efforts are centered on resolving the factors that control the rates of long-distance electron transfer reactions in proteins. These factors include (in addition to the distance and nature of the microenvironment separating the reactants) thermodynamic driving force and the configurational changes required upon reaction. Several of these aspects are addressed in this review, which is based primarily on recent work performed by the authors on model systems of blue copper-containing proteins. These proteins serve almost exclusively in electron transfer reactions, and as it turns out, their metal coordination sites are endowed with properties uniquely optimized for their function.

A progress report on a search for the lepton flavor violating reaction ?-+Ti->e-+Ti is presented. No evidence for this process has yet been found leading to an upper limit -11 (90% confidence level) relative to ordinary muon capture. (orig.)

Our KEK-RCNP-Osaka-ICEPP collaboration group led by Y. Masuda of IPNS, KEK and K. Hatanaka of RCNP, Osaka Univ. is developing a new type high intensity UCN (ultracold neutron) source at RCNP, Osaka Univ., for the future experiments on fundamental physics including n-EDM (neutron electric dipole moment) precision measurements, which may disclose origin of the baryon asymmetry in the present universe by providing active evidence of the violation of the time reversal invariance. Our UCN source produces 15 UCN/cm^3 at the exit, by the compact combination of the spallation neutron source and the super-fluid He-II moderator, which provides with the best power efficiency. In the present stage, we are trying to establish Ramsey resonance technique for the n-EDM measurements, by studying behavior of UCN and the polarization, using abundant UCNs produced in this source, in addition to the improvement of the source performance. The energy spectrum of UCN, i.e. the velocity distribution, is an important information in the estimation of the false EDM effect such as Bloch-Siegert shift and is found to be well reproduced by the uniform production in phase space. We tried to polarize UCN by the magnetic potential in pure ion foil. The production of polarization itself is found rather easy, namely, the polarization could reach as high as 100% in the beginning. Average polarization, however, is dominated by the relaxation of polarization during transportation and storage. For the n-EDM measurements in the next generation, our effort should be devoted to the understanding of the geometric phase such as Bloch-Siegert shift which dominates systematic error in the EDM measurements. Our next step will be demonstration of Ramsey resonance and the installation of the co-magnetometer and electric field, to detect geometric phase.

We propose indium (In) as a possible candidate for observing the permanent electric dipole moment (EDM) arising from the violations of parity (P) and time-reversal (T) symmetries. This atom has been laser cooled and therefore the measurement of its EDM has the potential of improving on the current best EDM limit for a paramagnetic atom which comes from thallium. We report the results of our calculations of the EDM enhancement factor due to the electronEDM and the ratio of the atomic EDM to the electron-nucleus scalar-pseudoscalar (S-PS) interaction coupling constant in In in the framework of the relativistic coupled cluster theory. It might be possible to get new limits for the electronEDM and the S-PS CP violating coupling constant by combining the results of our calculations with the measured value of the EDM of In when it is available. These limits could have important implications for the standard model (SM) of particle physics.

Possible ozone changes at 1 mb associated with the time variation and precipitation of relativistic electrons are investigated by examining the NIMBUS 7 SBUV ozone data set and corresponding temperatures derived from NMC data. No ozone depletion was observed in high-latitude summer when temperature fluctuations are small. In winter more variation in ozone occurs, but large temperature changes make it difficult to identify specific ozone decreases as being the result of relativistic electron precipitation.

We show that density functional theory calculations have reached an accuracy and speed making it possible to use them in conjunction with an evolutionary algorithm to search for materials with specific properties. The approach is illustrated by finding the most stable four component alloys out of the 192 016 possible fcc and bcc alloys that can be constructed out of 32 different metals. A number of well known and new "super alloys" are identified in this way.

A novel micromachining method to deposit a micro-3D spiral structure in air using electrical discharge machining (EDM) with a brass electrode was presented. During the deposition process, a 3D spiral structure is obtained only by the feed of the z-axis in the vertical direction. Furthermore, the obtained structure can be formed and repeated stably even in the upside-down direction under a gravity environment. It is seen that the material components of a micro-spiral structure are almost the same as those of an electrode by the energy spectrum analysis of a micro-spiral structure. According to scanning electron microscope photographs, the micro-spiral appears to feature a layered material organism structure and has compact bonding with the body material. In order to understand the forming mechanism of this kind of micro-spiral structure, simulation analysis is conducted. The track of the deposition particles can be obtained by simulation, which determines the shape of the deposited structure. According to the simulation results, the track of the deposition particles is consistent with that of EDM experiments. It is further found that the distribution of the electromagnetic field in a discharge channel has an important influence on the deposited structure and the track of the deposition particles.

Full Text Available In this paper new concept of manufacturing uses non-conventional energy sources like sound, light, mechanical, chemical, electrical, electrons and ions. With the industrial and technological growth, development of harder and difficult to machine materials, which find wide application in aerospace, nuclear engineering and other industries owing to their high strength to weight ratio, hardness and heat resistance qualities has been witnessed. New developments in the field of material science have led to new engineering metallic materials, composite materials and high tech ceramics having good mechanical properties and thermal characteristics as well as sufficient electrical conductivity so that they can readily be machined by spark erosion. Erosion pulse discharge occurs in a small gap between the work piece and the electrode. This removes the unwanted material from the parent metal through melting and vaporizing in presence of dielectric fluid. In recent years, EDM researchers have explored a number of ways to improve EDM Process parameters such as Electrical parameters, Non-Electrical Parameters, tool Electrode based parameters & Powder based parameters. This new research shares the same objectives of achieving more efficient metal removal rate reduction in tool wear and improved surface quality. This paper reviews the research work carried out from the inception to the development of Powder Mixed Dielectric electric Discharge Machining within the past decade. & also briefly describing the Current Research technique Trend in EDM & optimization Technique used in the Powder mix Electric Discharge Machining research field.

This paper explains four things in a unified way. First, how e-commerce can generate price equilibria where physical shops either compete with virtual shops for consumers with Internet access, or alternatively, sell only to consumers with no Internet access. Second, how these price equilibria might involve price dispersion on-line. Third, why prices may be higher on-line. Fourth, why established firms can, but need not, be more reluctant than newly created firm to adopt e-commerce. For this purpose we develop a model where e-commerce reduces consumers' search costs, involves trade-offs for consumers, and reduces retailing costs.

A card which does the signal processing for four SQUID amplifiers and two charge sensitive channels is described. The card performs the same functions as is presently done with two custom 9U x 280mm Eurocard modules, a commercial multi-channel VME digitizer, a PCI to GPIB interface, a PCI to VME interface and a custom built linear power supply. By integrating these functions onto a single card and using the power over Ethernet standard, the infrastructure requirements for instrumenting a Cold Dark Matter Search (CDMS) detector test stand are significantly reduced.

Effects caused by the electron electric dipole moment (EDM) in gadolinium garnets are considered. Experimental studies of these effects could improve current upper limit on the electronEDM by several orders of magnitude. We suggest a consistent theoretical model and perform calculations of observable effects in gadolinium gallium garnet and gadolinium iron garnet. Our calculation accounts for both direct and exchange diagrams.

We have been developing a high sensitivity atomic magnetometer for atomic EDM experiments using a lowfrequency nuclear spin maser. In the developed nuclear spin maser of 129Xe, suppression of drift and fluctuation in the magnetic field is one of the important issues. The magnetometer being developed for spin maser EDM experiments utilizes the nonlinear magneto optical rotation (NMOR) e_ect in Rb atomic vapor. The enhancement of the optical rotation in a small magnetic field relies on the long spin-coherence time of Rb atoms in a vapor cell. The NMOR spectrum was measured by using fabricated Rb cells coated with an anti-relaxation material. The NMOR spectrum dependence on laser frequency, cell coating, and laser beam diameter were investigated. The magnetic sensitivity at present is 0:2 ?G/?Hz from observed NMOR and noise spectra.

This article discusses the role of Energy Data Management (EDM) in a liberalised Swiss energy market in the light of increasing international dynamics in this area. The requirements placed on such EDM systems are reviewed and the changes necessary in the structures and processes of electricity supply organisations are discussed. A possible design for future software systems is presented. Such systems have to be flexible enough to cover various structural possibilities as Swiss legislation on the subject has not yet been passed. The handling of data on energy-flow balances when third-party power is transferred in shared mains systems is discussed and scheduling aspects of power generation and transmission are looked at. The billing of power to customers with a free choice of supplier is looked at, as is the situation involving utilities that supply not only electricity but gas, district heating and water too

Online information search is often seen as a highly utilitarian task but consumers' increasingly diverse ways of using the Web have brought forth more hedonic information search patterns. At the same time, the impact of electronic word-of-mouth (eWOM) on consumer purchase decisions is increasing. The purpose of this study is to investigate the differences between hedonic and utilitarian eWOM search patterns in the light of purchase value. Using survey data from 1660 customers of two travel ag...

This paper studies the obtaining of an experimental rapid drilling machine, through EDM process for small holes. The best parameters such as peak current, pulse frequency, duty factor and electrode rotation speed were studied for best machining characteristics. An electrolytic copper rod 0.8 mm diameter was selected as a tool electrode. The experiments generate output responses such as maximum material removal rate (MRR) and the dependence with peak current, duty factor and electrode rotation...

Micro Electro Discharge Machining is a well known process for machining microstructures with highest precision in hard and brittle or tough materials. The deeper the structures and therefore higher the aspect ratio, the more difficult it is to remove the ablated particles from the discharge zone and keep the process in stable condition. Flushing can be aided by vibration of either tool or workpiece. Thus, applying ultrasonic vibration to micro EDM has proven to enhance the process significant...

Electrical Discharge Machining (EDM) is a well-established machining option for manufacturing geometrically complex or hard material parts that are extremely difficult-to-machine by conventional machining processes. The non-contact machining technique has been continuously evolving from a mere tool and die making process. In this study, the influence of different electro discharge machining parameters (current, pulse on-time, pulse off-time, arc voltage) on the electrode wear ratio as a resul...

The recent miniaturization trend in manufacturing, has enhanced the production of new and highly sophisticated systems in various industrial fields. In recent years, machining of the so called difficult to cut materials has become an important issue in several sectors. Micro Electrical Discharge Machining (micro-EDM) thanks to its contactless nature, is one of the most important technologies for the machining of this type of materials and it can be considered as one of the most promising manu...

This paper reports an experimental investigation of EDM drilling of Ø2 mm holes on Inconel 718using brass electrode. The effect of process parameters (discharge current, pulse on and off times, andcapacitance) on process outputs (material removal rate and electrode wear rate) was determined based onminimum number of experiments. The mathematical modeling of process has been done using response surfacemethodology. The results show that the developed model can achieve reliable prediction of ex...

Full Text Available This paper reports an experimental investigation of EDM drilling of Ø2 mm holes on Inconel 718using brass electrode. The effect of process parameters (discharge current, pulse on and off times, andcapacitance on process outputs (material removal rate and electrode wear rate was determined based onminimum number of experiments. The mathematical modeling of process has been done using response surfacemethodology. The results show that the developed model can achieve reliable prediction of experimentalresults within acceptable accuracy

A proof-of-principle electron electric dipole moment (e-EDM)experiment using slow cesium atoms, nulled magnetic fields, and electricfield quantization has been performed. With the ambient magnetic fieldsseen by the atoms reduced to less than 200 pT, an electric field of 6MV/m lifts the degeneracy between states of unequal lbar mF rbar and,along with the low (approximately 3 m/s) velocity, suppresses thesystematic effect from the motional magnetic field. The low velocity andsmall residual magnetic field have made it possible to induce transitionsbetween states and to perform state preparation, analysis, and detectionin regions free of applied static magnetic and electric fields. Thisexperiment demonstrates techniques that may be used to improve the e-EDMlimit by two orders of magnitude, but it is not in itself a sensitivee-EDMsearch, mostly due to limitations of the laser system.

The search of high transverse momentum electrons needs the use of all the different elements of the UA2 detector; therefore the description of this search is a good way to understand the features of the apparatus, and its performance in a collider environment. We present a preliminary analysis of the UA2 data collected during the last Collider run (20 nb-1 integrated luminosity) with particular emphasis on large transverse momentum hadron jets and on electrons having the configuration expected from the decay of electroweak bosons

Electrical Discharge Machining (EDM) generates toxic substances, results in serious occupational health, and environmental issues, which influence the process parameters of EDM. These process parameters are multi-response parameters. The aim of this research is to solve the multi-response optimization problems and selection of optimum process parameters of green EDM using an integrated methodology comprising of entropy and Grey Relational Analysis (GRA). In this work, initially, an experiment was performed using Taguchi experimental technique. Thereafter, Entropy-GRA has been used to convert the multi-response parameters into single response parameter. Finally, the ranking of the parameter decides the best experimental set up and optimizes the input process parameters. In this work, Entropy method has been used to extract the precise value of each of the output parameters, which influences the gray relational grades for finding the optimal experimental set up. The justification of optimal input process parameters has been made using Analysis of Variance (ANOVA) analysis. An attempt has been made to compare the proposed methodology with the Fuzzy-TOPSIS and Taguchi-VIKOR methodology. The numerical result shows that the optimum process parameters are peak current (4.5 A), pulse duration (261 ?s), dielectric level (80 mm) and flushing pressure (0.3 kg/cm2).

Micro EDM is a known nonconventional process for the machining of hard to cut materials. Due to its ablating nature based on melting and evaporation through heat induced by electrical discharges it is independent of hardness, toughness or brittleness of the workpiece. Because of these benefits, EDM is widely used in tool- and mouldmaking; micro-EDM with its much lower discharge energies has been successfully applied to micromachining of high-accuracy parts. The precision manufacturing of high...

This paper aims to study on the feasibility of micron size hole manufacturing using micro Electric Discharge Machining (Micro-EDM). Main and auxiliary unit of the micro-EDM machine tool and their functions are described in some detail. The technological and electrical parameters that are effective in Micro-EDM are stated explicitly. Geometry of the machined micro-holes and resolidified material around the hole entrance are observed. Several descriptive pictures, obtained by Scanning Ele...

A recent search for single electron events performed with the ASP detector at PEP is presented. No anomalous signal is observed and limits on masses of the supersymmetric partners of the electron and photon are obtained. 7 refs., 1 fig

A recent search for single electron events performed with the ASP detector at PEP is presented. No anomalous signal is observed and limits on masses of the supersymmetric partners of the electron and photon are obtained. 7 refs., 1 fig.

Full Text Available Extrusion Honing (EH is also known as Abrasive flow machining (AFM is an effective method that is used to deburr, clean, polish, remove recast layer and micro cracks by flowing pressurized semisolid abrasive laden visco-elastic media over those surfaces. Inconel 625 is one of the most difficult-to-cut materials because of its low thermal diffusive property, high hardness and high strength at elevated temperature. In this paper, the influence of the process parameters on surface roughness is investigated on Inconel 625 material of square shape fabricated by Electric discharge machining (EDM. The processed surfaces were measured and analyzed with the help of surface roughness tester and Scanning Electron Microscope (SEM. Results show a significant improvement in surface finish and EH/AFM is capable of removing the micro cracks and recast layer.

Finnish Geodetic Institute (FGI) established in a co-operation with Posiva Ltd. high precision GPS networks at Olkiluoto, Kivetty and Romuvaara in 1994-1995. The goal of the work is to study local crustal deformations at the areas, which were selected as candidates for a disposal of spent nuclear fuel used in Finland. The studies are now concentrated at Olkiluoto, because the Government and the Parliament have ratified the positive policy decision that makes it possible to establish the final disposal at Olkiluoto. The GPS network at Olkiluoto includes ten reinforced concrete pillars located in different geological blocks. The FGI has observed the network semiannually since 1995. The GPS observations were made in 24 h sessions with Ashtech Z-12 GPS receivers equipped with Ashtech Dorne Margolin Choke Ring antennas. The computations were made with Bernese GPS software using the L1 and L2 frequencies and the ionosphere models. According to the 14 measurements campaigns the largest baselines change rates are about 0.5 mm ± 0.1-0.2 mm per year. We have noticed that some GPS sessions yield baseline lengths, which are systematically longer than the mean of all campaigns. The systematic error is most probably due to the ionosphere modeling. In order to solve this scaling problem we established a 511 m baseline for electronic distance measurements (EDM) between two pillars in the spring 2002. We will measure the distance between these stations with Mekometer 5000 during the GPS measurement campaigns. Two Mekometer measurements were performed in 2002. The differences between the GPS and the EDM measurements are few tenth of millimeter. More measurement campaigns are needed to determine possible crustal movements at the Olkiluoto investigation area. GPS observations and electronic distance measurements will be continued semiannually.

Full Text Available We report a data-mining investigation for the search of topological insulators by examining individual electronic structures for over 60,000 materials. Using a data-mining algorithm, we survey changes in band inversion with and without spin-orbit coupling by screening the calculated electronic band structure for a small gap and a change concavity at high-symmetry points. Overall, we were able to identify a number of topological candidates with varying structures and composition. Our overall goal is expand the realm of predictive theory into the determination of new and exotic complex materials through the data mining of electronic structure.

Full Text Available The MTV-G project was started in 2011 to explore a strong gravitational field at a nuclear scale in an electron double scattering experiment, utilizing an experimental technique of the MTV experiment, which searches a electron’s T-Violating transverse polarization in nuclear beta decay at TRIUMF-ISAC. In addition to this new experiment, we have also performed a re-analysis of spectroscopic data of exotic atoms, in a gravitational point of view. From these two studies, we set new constraints on possible new Yukawa interaction at sub-mm scale, as a test of gravitational inverse square law.

We propose to use ferroelectric (Eu,Ba)TiO$_3$ ceramics just above their magnetic ordering temperature for a sensitive electron electric dipole moment search. We have synthesized a number of such ceramics with various Eu concentrations and measured their properties relevant for such a search: permeability, magnetization noise, and ferroelectric hysteresis loops. The results of our measurements indicate that a search for the electron electric dipole moment with Eu$_{0.5}$Ba$_...

The PbF molecule is particularly suited to a search for the electron's electric dipole moment (e-EDM.) In addition to its sensitivity to an e-EDM, its ^2?1/2 ground state provides for a small magnetic moment. Furthermore, this small magnetic moment vanishes at a magic value of electric field. This vanishing point has an experimentally observable signature: When a beam of suitably aligned ground state PbF molecules is allowed to traverse a region of electric and magnetic fields, the polarization is conserved when the electric field matches this magic value. By measuring the (molecular-frame)magnitude of this magic electric field for the case that the electric field is parallel or antiparallel to the magnetic field, sensitivity to the e-EDM is achieved. Progress toward this measurement, including the development of a continuous molecular beam source of PbF, characterization of the electronic, rotational, and hyperfine structure of the molecule, the achievement of an ultra-sensitive continuous ionization detection scheme, and the construction of a Ramsey- resonance machine are briefly summarized.

In scanning micro electrical discharge machining (EDM), the machining time for a 3D mould cavity is longer due to the smaller discharge area of a thin wire tool electrode. Moreover, a stable discharge area is hardly kept because of the scanning motion, resulting in a lower discharge ratio. To improve the machining process, a method of workpiece vibration-assisted servo scanning 3D micro EDM is developed. 3D micro structures are machined by tool electrode scanning layer by layer according to the numerical control (NC) code. Micro-amplitude assisting vibration is realized by adopting a piezoelectric (PZT) actuator driven by high-frequency sinewave voltage. Tool electrode wear is real-time compensated in the axial direction by keeping a discharge gap. A number of experiments were carried out to machine a micro rectangular cavity (900 µm × 600 µm), and the process model of vibration-assisted servo scanning EDM was established. In addition, several typical 3D micro structures have been machined. The process-model analysis and the experimental results show that the occurring frequency of the favorable discharge gap increases obviously during the machining process assisted with high-frequency vibration, so that the machining stability and the effective discharge ratio are improved. The machining efficiency increases to 6.5 times at the assisting vibration frequency of 5 kHz and the amplitude of 2.7 µm, and the material removal rate on red copper plate reaches about 1.4 n red copper plate reaches about 1.4 × 105 µm3 s?1 with a tool electrode of 100 µm in diameter

A search for excited states of the standard model fermions was performed using the ZEUS detector at the HERA electron-proton collider, operating at a centre of mass enery of 296 GeV. In a sample corresponding to an integrated luminosity of 0.55 pb-1, no evidence was found for any resonant state decaying into final states composed of a fermion and a gauge boson. Limits on the coupling strength times branching ratio of excited fermions are presented for masses between 50 GeV and 250 GeV, extending previous search regions significantly. (orig.)

Electrical discharge machining is a popular non-traditional machining process, optimum for accurate machining of complex geometries in hard materials. EDM has been used for decades for machining pieces for the aeronautical industry, but surface integrity, and consequently the reliability of the machined parts have been questioned for long time due to the thermal nature of this machining process. In recent years, efforts have been put on modeling of the EDM process, being thermal modeling of the process one promising alternative. In a previous publication an original model of the EDM process was presented and it was used to predict material removal rate and surface finish for the EDM of steel. In the present article the capability of that modeling tool to characterize discharge properties and to predict recast layer distribution when EDMing an aeronautical alloy will be analyzed. EDM process of Inconel 718 has been studied and discharge properties have been obtained for four different EDM regimes. The capability of the model to reflect the behavior of more energetic regimes is discussed. Gathered information has been used to simulate the evolution of the recast layer generation process. Obtained results have been validated comparing them with experimental measurements, revealing a good correlation between predictions and experimental data. Finally, energetic efficiency of the discharge process has been simulated for the adjusted EDM regimes.

Flavor-changing terms with CP-violating phases in the quark sector may contribute to the hadronic electric dipole moments (EDMs). However, within the Standard Model (SM), the source of CP violation comes from the unique CKM phase, and it turns out that the EDMs are strongly suppressed. This implies that the EDMs are very sensitive to non-minimal flavor violation structures of theories beyond the SM. In this Letter, we discuss the quark EDMs and CEDMs (chromoelectric dipole moments) in the MSSM with general flavor-changing terms in the squark mass matrices. In particular, the charged-Higgs mediated contributions to the down-quark EDM and CEDM are evaluated at two-loop level. We point out that these two-loop contributions may dominate over the one-loop induced gluino or higgsino contributions even when the squark and gluino masses are around few TeV and tan? is moderate

A fatigue study was undertaken to determine how much electrical-discharge-machine (EDM) processing affected the fatigue life of balance materials: EDM and regular milling-machine (MM) samples were compared. Simulation of a typical balance stress configuration was devised for the fatigue testing in order to obtain results more closely related to balance situations. The fatigue testing of the EDM and MM specimens has indicated that the EDM technique does indeed reduce the fatigue life of 15-5PH steel, the first balance material tested. This conclusion was based on comparisons of the specimen fatigue lives with theoretical and manufacturer's data. Hence the EDM surface effects are detrimental to the fatigue life of this balance material.

We propose indium (In) as a possible candidate for observing the permanent electric dipole moment (EDM) arising from violations of parity (P) and time-reversal (T) symmetries. This atom has been laser cooled and therefore the measurement of its EDM has the potential of improving on the current best EDM limit for a paramagnetic atom, which comes from thallium. We report the results of our calculations of the EDM enhancement factor due to the electronEDM and the ratio of the atomic EDM to the electron-nucleus scalar-pseudoscalar (S-PS) interaction coupling constant in In within the framework of the relativistic coupled cluster theory. It might be possible to get new limits for the electronEDM and the S-PS CP-violating coupling constant by combining the results of our calculations with the measured value of the EDM of In when it is available. These limits could have important implications for the standard model (SM) of particle physics.

Wire electrical discharge machining (Wire EDM) is a non-conventional metal removal process as well as one of the best manufacturing processes suitable for producing jigs, fixtures, and dies. Among others, the machine is able to cut a workpiece having oblique and taper form. The objective of this paper is to optimize the input parameters of Wire EDM machine, such as no load voltage, capacitor, on-time, off-time, and servo voltage, for machining medium carbon steel ASSAB 760. The Taguchi design of experiments, the signal-to-noise ratio, and analysis of variance are employed to analyze the effects of the input parameters by adopting L18 Taguchi orthogonal array (OA) to conduct experiments using brass wire electrode of 0.2 mm in diameter. In order to achieve the maximum material removal rate (MRR) or the minimum surface roughness (SR), six controllable factors, i.e., the parameters of each at three levels are applied for determining the optimal combination of factors and levels. The results reveal that the MRR and the SR are greatly influenced by the on-time and the taper angle, respectively. Experimental results affirm the effectiveness of the method, and also prove that the Taguchi method is suitable to solving the stated problem within minimum number of experiments as compared to that of a full factorial design.

A search for the non-conservation of lepton flavor in the decay tau -> electron gamma has been performed with 2.07 x 10^8 e+e- -> tau+ tau- events collected by the BABAR detector at the PEP-II storage ring at a center-of-mass energy near 10.58 GeV. We find no evidence for a signal and set an upper limit on the branching ratio of BR(tau -> electron gamma) < 1.1 x 10^-7 at 90% confidence level.

The MTV-G project was started in 2011 to explore a strong gravitational field at a nuclear scale in an electron double scattering experiment, utilizing an experimental technique of the MTV experiment, which searches a electron's T-Violating transverse polarization in nuclear beta decay at TRIUMF-ISAC. In addition to this new experiment, we have also performed a re-analysis of spectroscopic data of exotic atoms, in a gravitational point of view. From these two studies, we set new constraints on possible new Yukawa interaction at sub-mm scale, as a test of gravitational inverse square law.

Based on the high sensitivity of Compton scattering off ultra relativistic electrons, the possibility of anisotropies in the speed of light is investigated. The result discussed in this contribution is based on the gamma-ray beam of the ESRF's GRAAL facility (Grenoble, France) and the search for sidereal variations in the energy of the Compton-edge photons. The absence of oscillations yields the two-sided limit of 1.6 x 10^{-14} at 95 % confidence level on a combination of photon and electron coefficients of the minimal Standard Model Extension (mSME). This new constraint provides an improvement over previous bounds by one order of magnitude.

The necessity to preserve the knowledge gained in the process of fast reactors development and operation is quite obvious. For this purpose it is necessary to set up electronic libraries and suitable search systems. All the documents that contain certain information about the objects from the given field of knowledge can be referred to as sources of knowledge, i.e. they are articles, preprints, papers, clarification notes, reports, catalogs and other sources. These sources of knowledge can be found in various places, institutions, archives, etc. Usually they are kept in libraries. These sources can have different forms, e.g. electronic, printed, photo, microfiche, etc. The information about these sources of knowledge is placed in catalogs that make the process of searching for required documents much easier. Catalogs usually have a subject heading identifier, index of authors, index of topics, key words and summaries. In a certain sense, catalogs can be also considered as sources of knowledge. There are a lot of various sources of knowledge and experience in the nuclear industry under the subject of 'Fast Reactors'. All of them are in different states in terms of convenience of their use and even possibility to use this knowledge and experience once again. In the best case these sources are in the form of electronic documents that contain not only the information about certain knowledge and experience but this very knowledge and experience in the digitized electronic nd experience in the digitized electronic form. These types of catalogs are the most suitable and simple for their use. There are libraries where knowledge and experience are only kept as nondigitized images of documents. It is not so convenient to work with this information but still it is quite real to get it. If a catalogs only contains information about knowledge and experience but neither is available in electronic form, then in order to get the access to this information it will be necessary either to digitize it or to get its non-electronic copy (usually, hard copy). But even if the entire scope of information about knowledge and experience is presented in electronic catalogs, nevertheless there will be a certain problem to work with it, as to work with a lot of intangible sources may turn out to be much more time- and labor-consuming than to work with it within a single system. Two problems have to be solved in terms of knowledge preservation. The first one is related to transformation of all the sources into electronic form. The second one is related to effective search for the required information by means of the catalogs available. The first problem can be solved rather easily. All the published sources of knowledge can be scanned and transformed into electronic form. Thus, instead of printed catalogs that contain the information about sources of knowledge there will be electronic catalogs. Though this activity seems rather simple, it is still very labor-and time-consuming, because the number of these sources is tremendous. We cannot say that the first problem can be promptly solved because it will require not only great financial expenses but also significant organizational efforts. To solve the second problem is much more complicated, as currently there are no effective search systems oriented towards a specific field of knowledge that could run in heterogeneous and worldwide search environment. At the same time this problem can be solved much faster than the first one, because in this case we mean the development of a software product independent of any organizational measures. The conditions required to cope with this problem imply the availability of electronic catalogs that contain the information about sources of knowledge and their accessibility in the computer network

The e?cient identi?cation of high energy electrons at the Large Hadron Collider (LHC) is of primary importance for the study of many physics processes, like the search for the Higgs boson and other Standard Model and beyond Standard Model processes. For the measurement of the electron energy, the CMS exp eriment uses a high precision Electromagnetic Calorimeter (ECAL). It is divided into a barrel and two end-caps composed of lead tungstate crystals, which are read by photo detectors. The integration of the ECAL readout electronics into the structure of the ECAL, the testing strategy, and the current performance of the ECAL electronics are presented in detail. In February 2010, 99.6% of the 75 848 ECAL readout channels were found to be fully operational. The identi?cation of isolated electrons with the CMS detector is discussed, focusing on the reduction of the fake rate, i.e. the rate of jets or photons that are miss-identi?ed as electrons. Tools for the electron selection are introduced, and a simple...

This paper presents the results of experimental studies carried out to conduct a comprehensive investigation on the influence of ultrasonic vibration of workpiece on the characteristics of Electrical Discharge Machining (EDM) process of FW4Welding Metal in comparison with the conventional EDM process. The studied process characteristics included the material removal rate (MRR), tool wear ratio (TWR), and surface roughness ( R a and R max) of the workpiece after the EDM and ultrasonic assisted EDM (US-EDM) processes. The experiments performed under the designed full factorial procedure and the considered EDM input parameters included pulse on-time and pulse current. The experimental results show that in short pulse on-times, material removal rate in the USEDM process is approximately quadruple than that of the EDM process. On the contrary, in the long pulse on-times, ultrasonic vibration of workpiece leads to the reduction in the MRR. On the other hand, in short pulse on-times, the TWR in the US-EDM process is lower than that of in the EDM process, and this condition reverses with increase in the pulse on-time. Furthermore, the surface roughness of the workpiece machined by EDM process is slightly lower than that of applied to the US-EDM process.

Electrical discharge machining (EDM) is one of the most accurate non traditional manufacturing processes available for creating tiny apertures, complex or simple shapes and geometries within parts and assemblies. Performance of the EDM process is usually evaluated in terms of surface roughness, existence of cracks, voids and recast layer on the surface of product, after machining. Unfortunately, the high heat generated on the electrically discharged material during the EDM process decreases the quality of products. Carbon nanotubes display unexpected strength and unique electrical and thermal properties. Multi-wall carbon nanotubes are therefore on purpose added to the dielectric used in the EDM process to improve its performance when machining the AISI H13 tool steel, by means of copper electrodes. Some EDM parameters such as material removal rate, electrode wear rate, surface roughness and recast layer are here first evaluated, then compared to the outcome of EDM performed without using nanotubes mixed to the dielectric. Independent variables investigated are pulse on time, peak current and interval time. Experimental evidences show that EDM process operated by mixing multi-wall carbon nanotubes within the dielectric looks more efficient, particularly if machining parameters are set at low pulse of energy.

Electrical discharge machining (EDM) is one of the most accurate non traditional manufacturing processes available for creating tiny apertures, complex or simple shapes and geometries within parts and assemblies. Performance of the EDM process is usually evaluated in terms of surface roughness, existence of cracks, voids and recast layer on the surface of product, after machining. Unfortunately, the high heat generated on the electrically discharged material during the EDM process decreases the quality of products. Carbon nanotubes display unexpected strength and unique electrical and thermal properties. Multi-wall carbon nanotubes are therefore on purpose added to the dielectric used in the EDM process to improve its performance when machining the AISI H13 tool steel, by means of copper electrodes. Some EDM parameters such as material removal rate, electrode wear rate, surface roughness and recast layer are here first evaluated, then compared to the outcome of EDM performed without using nanotubes mixed to the dielectric. Independent variables investigated are pulse on time, peak current and interval time. Experimental evidences show that EDM process operated by mixing multi-wall carbon nanotubes within the dielectric looks more efficient, particularly if machining parameters are set at low pulse of energy.

We demonstrate that electric dipole moments (EDMs) strongly constrain possible SUSY contributions to the CP asymmetries of B processes; LL and/or RR flavour mixings between second and third generations are severely restricted by the experimental limit on the mercury EDM, and so therefore are their possible contributions to the CP asymmetries of B --> \\phi K and B --> \\eta' K. We find that SUSY models with dominant LR and RL mixing through non-universal A-terms is the only way to accommodate the apparent deviation of CP asymmetries from those expected in the Standard Model without conflicting with the EDM bounds or with any other experimental results.

We demonstrate that electric dipole moments (EDMs) strongly constrain possible SUSY contributions to the CP asymmetries of B processes; LL and/or RR flavour mixings between second and third generations are severely restricted by the experimental limit on the mercury EDM, and so therefore are their possible contributions to the CP asymmetries of B->?K and B->?'K. We find that SUSY models with dominant LR and RL mixing through non-universal A-terms is the only way to accommodate the apparent deviation of CP asymmetries from those expected in the Standard Model without conflicting with the EDM bounds or with any other experimental results

Since traditional handling mechanisms have an unpredictable behavior at micro scale, micro-assembly is a bottleneck in the development of hybrid micro-systems, and the development of new approaches is strongly demanded. In this paper, a recent study of the fabrication of a ceramics vacuum micro-gripper to handle parts in the range of hundreds of microns (300-1000) is presented. Among the possible micro manufacturing processes, micro-EDM has been selected as proving to be a very competitive fabrication technology for the manufacturing of ultra miniature components and micro sized features. The influence of the process parameters on the machining performance of interest is firstly investigated; then, the experimental results on machining the micro gripper are presented, finally concluding remarks are given.

Since traditional handling mechanisms have an unpredictable behavior at micro scale, micro-assembly is a bottleneck in the development of hybrid micro-systems, and the development of new approaches is strongly demanded. In this paper, a recent study of the fabrication of a ceramics vacuum micro-gripper to handle parts in the range of hundreds of microns (300-1000) is presented. Among the possible micro manufacturing processes, micro-EDM has been selected as proving to be a very competitive fabrication technology for the manufacturing of ultra miniature components and micro sized features. The influence of the process parameters on the machining performance of interest is firstly investigated; then, the experimental results on machining the micro gripper are presented, finally concluding remarks are given.

Full Text Available Electrical Discharge Machining (EDM is a well-established machining option for manufacturing geometrically complex or hard material parts that are extremely difficult-to-machine by conventional machining processes. The non-contact machining technique has been continuously evolving from a mere tool and die making process. In this study, the influence of different electro discharge machining parameters (current, pulse on-time, pulse off-time, arc voltage on the electrode wear ratio as a result of application copper electrode to hot work steel DIN1.2344 has been investigated. Design of the experiment was chosen as full factorial. Artificial neural network has been used to choose proper machining parameters and to reach certain electrode wear ratio. Finally a hybrid model has been designed to reduce the artificial neural network errors. The experiment results indicated a good performance of proposed method in optimization of such a complex and non-linear problems.

The spin torque of the electron is studied in relation to the electric dipole moment (EDM) of the electron. The spin dynamics is known to be given by the spin torque and the zeta force in quantum field theory. The effect of the EDM on the torque of the spin brings a new term in the equation of motion of the spin. We study this effect for a solution of the Dirac equation with electromagnetic field.

We report recent results from an experimental search for Lorentz and CPT-violating forces coupling to spin-polarized electrons. We record the torque on a pendulum containing 10^23 polarized electrons as a function of its angle with respect to large sources of spin-polarized electrons placed outside the torsion balance apparatus or with respect to a Lorentz-violating background field fixed in space. Our constraints on the background field are complementary to constraints in the proton and neutron sectors from maser and co-magnetometer experiments. Spin-spin results can be interpreted as constraints on axion-like pseudoscalar couplings, the exchange of low-mass bosons constrained only by rotational and translational invariance, and on forces mediated by the Nambu-Goldstone bosons that would arise in the context of spontaneously broken Lorentz symmetry. These Goldstone bosons, often referred to as the ``ghost condensate" because they have a negative kinetic term in the Lagrangian stabilized by higher order terms, are particularly interesting because the energy scale accessible to our experiment is the scale on which they could contribute either to Dark Energy or Dark Matter. We will present preliminary results from the first experimental search for the unique signature of the ghost condensate's interaction with Standard Model fermions.

This is the theoretical review of exploration of new physics beyond the Standard Model (SM) in electric dipole moment (EDM) in elementary particles, atoms, and molecule. EDM is very important CP violating phenomenon and sensitive to new physics. Starting with the estimations of EDM of quarks-leptons in the SM, we explore the new signals beyond the SM. However, these works drive us to more wide fronteers where we serach fundamental physics using atoms and molecules and vice versa. Paramagnetic atoms and molecules have great enhancement factor on electronEDM. Diamagnetic atoms and molecules are very sensitive to nuclear P and T odd processes. Thus EDM becomes the key word not only of New Physics but also of unprecedented fruitful collaboration among particle, atomic. molecular physics. This review intends to help such collaboration over the wide range of physicists.

We propose to use ferroelectric (Eu,Ba)TiO$_3$ ceramics just above their magnetic ordering temperature for a sensitive electron electric dipole moment search. We have synthesized a number of such ceramics with various Eu concentrations and measured their properties relevant for such a search: permeability, magnetization noise, and ferroelectric hysteresis loops. The results of our measurements indicate that a search for the electron electric dipole moment with Eu$_{0.5}$Ba$_{0.5}$TiO$_3$ should lead to an order of magnitude improvement on the current best limit.

We analyze the charm quark electric dipole moment (EDM) in the minimal supersymmetric extension of the standard model (MSSM), including important two-loop gluino contributions. Considering the experimental constraint on the neutron EDM, the theoretical prediction for the charm quark EDM can reach about $10^{-20}e\\cdot cm$. If taking into account the mixing between the scharm and stop quarks in the effective supersymmetry scenario, the charm quark EDM can be enhanced to $\\sim 10^{-19}e\\cdot cm$. Direct production of the CP-odd $^1P_1$ state $h_c$ in $e^+e^-$ annihilation via the CP-violating process at the BES-III and CLEO-C is analyzed.

The electrode wear in micro-electrical discharge milling (micro-EDM milling) is one of the main problems to be solved in order to improve machining accuracy. This paper presents an investigation on wear and material removal in micro-EDM milling for selected process parameter combinations typical of rough and finish machining of micro-features in steel. The experiments were performed on state-of-the-art micro-EDM equipment. Based on discharge counting and volume measurements, electrode wear per discharge and material removal per discharge were measured for several energy levels. The influence of the accuracy of volume measurements on the electrode wear per discharge and on the material removal per discharge are discussed, and the issues limiting the applicability of real time wear sensing in micro-EDM milling are presented.

Electric discharge machining (EDM) has achieved remarkable success in the manufacture of conductive ceramic materials for the modern metal industry. The mathematical models are proposed for the modeling and analysis of the effects of machining parameters on the performance characteristics in the EDM process of WC/5Ni, Which is produced through powder metallurgy route. Response surface methodology (RSM)is used to explain the influences of four machining parameters ; tool rotational speed(S), d...

Problem statement: Electrical Discharge Machining (EDM) has grown over the last few decades from a novelty to a mainstream manufacturing process. Though, EDM process is very demanding but the mechanism of the process is complex and far from completely understood. It is difficult to establish a model that can accurately predict the performance by correlating the process parameters. The optimum processing parameters are essential to increase the production rate and decrease the machining...

Observation of a nonzero EDM would imply CP violation beyond the Standard Model. The most precise EDM limit, established by our group several years ago for ^199Hg, is |dHg| magnetic and anti- parallel electric fields, resulting in EDM-sensitive spin precession; the remaining cells, at zero electric field, serve to cancel magnetic gradient noise and limit systematics due to charging and leakage currents. To date, the statistical uncertainty for the new EDM data is ± 1.7x10-29 e cm, a 3x improvement over our previous measurement. Constraining systematics at similar levels requires mitigating Stark interference, an EDM-mimicking vector light shift that is linear in the electric field. To this end, we have explored averaging data at two probe wavelengths where the Stark interference light shift is equal but opposite. Alternatively, this effect can be eliminated by determining the Larmor frequency ``in the dark'' between two probe pulses that establish the Larmor phase at the beginning and end of the dark period. We are currently implementing this latter scheme. We will discuss progress on an improved measurement of the ^199 Hg EDM.

Micro-gas turbine engine (MTE) rotor is an important indicator of its property, therefore, the manufacturing technology of the microminiature rotor has become a hot area of research at home and abroad. At present, the main manufacturing technologies of the MTE rotor are directed forming fabrication technologies. However, these technologies have a series of problems, such as complex processing technology high manufacturing cost, and low processing efficiency, and so on. This paper takes advantage of micro electric discharge machining (micro-EDM) in the field of microminiature molds manufacturing, organizes many processing technologies of micro-EDM reasonably to improve processing accuracy, presents an integrated micro-EDM technology and its process flow to fabricate MTE rotor die, and conducts a series of experiments to verify efficiency of this integrated micro-EDM. The experiments results show that the MTE rotor die has sharp outline and ensure the good consistency of MTE rotor blades. Meanwhile, the MTE rotor die is applied to micro extrusion equipment, and technologies of micro-EDM and micro forming machining are combined based on the idea of the molds manufacturing, so the MTE rotor with higher aspect ratio and better consistency of blades can be manufactured efficiently. This research presents an integrated micro-EDM technology and its process flow, which promotes the practical process of MTE effectively.

The first dedicated search for Higgs bosons decaying into tau pairs with two electrons and 4 neutrinos in the final state is presented. The search is performed with the CMS detector at the LHC based on an integrated luminosity of 4.9 fb-1 and 19.7 fb-1 at 7 TeV and 8 TeV, respectively. Events with two reconstructed electrons are selected before extensive multivariate analysis techniques are utilized to achieve an optimal background rejection. The ee-channel alone excludes 3.2 x (?HSM x BR(H???)) for mH=120 GeV/c2 and 3.7 x (?HSM x BR(H???)) for mH=125 GeV/c2 at 95% confidence level. The ee-channel is combined into the official CMS H??? analysis, to find, for the first time, direct evidence for couplings of the new Higgs-like boson to down-type fermions with 3.20?.

The first dedicated search for Higgs bosons decaying into tau pairs with two electrons and 4 neutrinos in the final state is presented. The search is performed with the CMS detector at the LHC based on an integrated luminosity of 4.9 fb{sup -1} and 19.7 fb{sup -1} at 7 TeV and 8 TeV, respectively. Events with two reconstructed electrons are selected before extensive multivariate analysis techniques are utilized to achieve an optimal background rejection. The ee-channel alone excludes 3.2 x (?{sup H}{sub SM} x BR(H???)) for m{sub H}=120 GeV/c{sup 2} and 3.7 x (?{sup H}{sub SM} x BR(H???)) for m{sub H}=125 GeV/c{sup 2} at 95% confidence level. The ee-channel is combined into the official CMS H??? analysis, to find, for the first time, direct evidence for couplings of the new Higgs-like boson to down-type fermions with 3.20?.

We have searched for time modulation of the electron capture decay probability of 142Pm in an attempt to confirm a recent claim from a group at the Gesellschaft fuer Schwerionenforschung (GSI). We produced 142Pm via the 124Sn(23Na, 5n)142Pm reaction at the Berkeley 88-Inch Cyclotron with a bombardment time short compared to the reported modulation period. Isotope selection by the Berkeley Gas-filled Separator is followed by implantation and a long period of monitoring the 142Nd K? x-rays from the daughter. The decay time spectrum of the x-rays is well-described by a simple exponential and the measured half-life of 40.68(53) seconds is consistent with the accepted value. We observed no oscillatory modulation at the proposed frequency at a level 31 times smaller than that reported by Litvinov et al. [Y.A. Litvinov, et al., Phys. Lett. B 664 (2008) 162]. A literature search for previous experiments that might have been sensitive to the reported modulation uncovered another example in 142Eu electron-capture decay. A reanalysis of the published data shows no oscillatory behavior

We report on a direct lattice calculation of the neutron EDM(NEDM) using the external electric field method in both quenched and full QCD. In quenched QCD, we use a $24^3\\times 32$ lattice at $\\beta=2.6$ with the Iwasaki gauge action and the clover fermion action to examine the viability of this method. In particular we investigate possible effects of violation of the periodic boundary condition of the external electric field on the NEDM signal. We also study the quark mass dependence of NEDM in quenched QCD, and observe that NEDM seems to remain non-zero toward the chiral limit because of the quenched artifact. In 2-flavor full QCD we employ configurations generated by the CP-PACS collaboration on a $24^3\\times 48$ lattice at $\\beta=2.1$ with the same gluon and quark actions as in the quenched case. Since the number of configurations is limited, we employ 8 different source points per one configuration and take an average over them. Our preliminary result at three quark masses ($m_{PS}/m_V\\simeq 0.81, 0.76, ...

The electrode wear in micro electrical discharge milling (micro EDM milling) is one of the main problems to be solved in order to improve machining accuracy. Most common, the electrode wear is measured on machine by touching the reference point with the tip of the electrode (Touch method) after machining a certain number of layers. The reduction of the electrode length due to the wear (linear wear) is used to modify the electrode trajectory. A laser scan micrometer (LSM) is implemented on the machine mostly to acquire electrode profiles after dressing of the electrode is applied. It is also an alternative solution to measure the linear and volumetric wear, which in principle should be more accurate compared to the measurements performed by The Touch method. In this paper, the performance of the two systems, namely Touch and LSM, were compared. The experimental results show that the accuracy of the electrode length measurement by the Touch method is enough accurate for the linear wear estimation, but the volumetric wear should be measured by LSM system.

Alkali-doped aromatic compounds have shown evidence of metallic and superconducting phases whose precise nature is still mysterious. In potassium and rubidium-doped phenanthrene, superconducting temperatures around 5 K have been detected, but such basic elements as the stoichiometry, crystal structure, and electronic bands are still speculative. We seek to predict the crystal structure of M3-phenanthrene (M = K, Rb) using ab initio evolutionary simulation in conjunction with density functional theory (DFT), and find metal but also insulator phases with distinct structures. The original P21 herringbone structure of the pristine molecular crystal is generally abandoned in favor of different packing and chemical motifs. The metallic phases are frankly ionic with three electrons acquired by each molecule. In the nonmagnetic insulating phases the alkalis coalesce reducing the donated charge from three to two per phenanthrene molecule. A similar search for K3-picene yields an old and a new structure, with unlike potassium positions and different electronic bands, but both metallic retaining the face-to-edge herringbone structure and the P21 symmetry of pristine picene. Both the new K3-picene and the best metallic M3-phenanthrene are further found to undergo a spontaneous transition from metal to antiferromagnetic insulator when spin polarization is allowed, a transition which is not necessarily real, but which underlines the necessity to include correlations beyond DFT. Features of the metallic phases that may be relevant to phonon-driven superconductivity are underlined.

SuperCDMS, a direct search for WIMPs, is currently operating a 9-kg array of cryogenic germanium (Ge) detectors in the Soudan Underground Laboratory. These detectors, known as iZIPs, use ionization and phonon sensors placed symmetrically on both sides of a Ge crystal to measure both charge and athermal phonons from each particle interaction. The information from each event provides excellent discrimination between electron recoils and nuclear recoils, as well as discrimination between events on the detector surface and those in the interior. To demonstrate the surface electron rejection capabilities, two $^{210}$Pb sources were installed facing detectors, producing $\\sim$130 beta decays/hr. In $\\sim$800 live hours, no events leaked into the WIMP signal region in the recoil energy range 8--115 keVr, providing an upper limit to the surface event leakage fraction of $1.7 \\times 10^{-5}$ at 90% C.L. This rejection factor demonstrates that surface electrons would produce $< 0.6$ event background in the 0.3 ton-...

Two experiments on DIII-D have been performed with the purpose of searching for evidence of a critical electron temperature gradient or gradient scale length. Both experiments employed off-axis EC heating to vary the local value of ?Te/Te while holding the total heating power and thus edge temperatures constant. No evidence of an inverse critical gradient scale length, kcrit, was observed in these experiments, but the existence of one cannot be ruled out by the experimental results. If kcrit exists, the experimental results indicate kcrit -1 at ? = 0.45 and kcrit -1 at ? = 0.29 corresponding to a critical gradient scale length larger than 43% and 65% of the plasma minor radius, respectively. Models other than one based on kcrit are also consistent with the experimental observations. (author)

A search for new long-lived particles decaying to leptons is presented using proton-proton collisions produced by the LHC at $\\sqrt{s}$ = 8 TeV. Data used for the analysis were collected by the CMS detector and correspond to an integrated luminosity of 19.7 fb$^{-1}$. Events are selected with an electron and a muon that have transverse impact parameter values between 0.02 cm and 2 cm. The search has been designed to be sensitive to a wide range of models with non-prompt e-$\\mu$ final states. Limits are set on the ''displaced supersymmetry'' model, with pair production of top squarks decaying into an e-$\\mu$ final state via R-parity violating interactions. The results are the most restrictive to date on this model, with the most stringent limit being obtained for a top squark lifetime corresponding to $c\\tau$ = 2 cm, excluding masses below 790 GeV at 95% confidence level.

We have searched for time modulation of the electron capture decay probability of $^{142}$Pm in an attempt to confirm a recent claim from a group at the Gesellschaft f\\"{u}r Schwerionenforschung (GSI). We produced $^{142}$Pm via the $^{124}$Sn($^{23}$Na, 5n)$^{142}$Pm reaction at the Berkeley 88-Inch Cyclotron with a bombardment time short compared to the reported modulation period. Isotope selection by the Berkeley Gas-filled Separator is followed by implantation and a long period of monitoring the $^{142}$Nd K$_{\\alpha}$ x-rays from the daughter. The decay time spectrum of the x-rays is well-described by a simple exponential and the measured half-life of 40.68(53) seconds is consistent with the accepted value. We observed no oscillatory modulation at the proposed frequency at a level 31 times smaller than that reported by Litvinov {\\it et al.} (Phys. Lett. B 664 (2008) 162; arXiv:0801.2079 [nucl-ex]). A literature search for previous experiments that might have been sensitive to the reported modulation unco...

Data taken by the DELPHI experiment at a centre-of-mass energy of 189 GeV and an integrated luminosity of 158 pb-l have been used to search for the supersymmetric partners of the electrons (the selectrons, e-tilde) and muons (the smuons, ?-tilde) in the context of the Minimal Supersymmetric Standard Model (MSSM). Assuming R-parity conservation, sleptons can be pair-produced at the Large Electron-Positron (LEP) collider. The decay topology studied was the direct decay to the lightest neutralino (X-tilde10) and the corresponding lepton (l-tilde ? lX-tilde10) of same flavour. Within the context of the MSSM, the lightest neutralino forms an ideal candidate for the lightest supersymmetric particle (LSP) and, as it interacts only weakly with ordinary matter, escapes detection. Such events are therefore characterised by acoplanar lepton-pairs coupled with missing energy. The observed number of event candidates from both searches were compatible with Standard Model expectations. Results have therefore been interpreted in terms of excluded regions in the slepton-neutralino mass plane. Assuming the MSSM input parameters for the ratio of the vacuum expectation values of the two Higgs doublets, tan?=1.5 and the Higgs mass mixing parameter, ? = -200 GeV/c2, the 95 % CL excluded mass regions for right-handed selectrons and smuons were, respectively, me-tildeR ? 90 GeV/c2 and m?-tildGeV/c2 and m?-tilder ? 70 GeV/c2. Both these results are interpreted for light neutralino masses and are consistent with other measurements at LEP experiments. (author)

We show that in the MSSM without R-parity symmetry there are no new contributions to electron and neutron electric dipole moments (EDMs) at 1-loop induced by the R-parity violating Yukawa couplings. Non-zero EDMs for the electron and neutron first arise at the 2-loop level. As an example we estimate the contribution of a two-loop graph which induces electronEDMs. On the other hand, we show that the (Majorana) neutrino electric and magnetic transition moments are non-zero even at the 1-loop level. Constraints on the R-parity violating couplings are derived from the existing bounds on the neutrino dipole moments.

Theoretical studies are presented how the electric dipole moment (EDM) of the electron in H-like ions in electrostatic storage rings can sensitively be determined. With the proposed experiments a new constraint of about $10^{-29}$ e cm for the electronEDM can be established what is by an order of magnitude more restrictive than the existing bounds. Experiments with H-like ions may provide a possibility to distinguish between the electronEDM effect and the effect of P,T violating interaction between the atomic electron and the nucleus.

We propose an experiment intended for search for an admixture of sterile neutrino with mass m$_s$ in the range of 1-8 keV that may be detected as specific distortion of the electron energy spectrum during tritium decay. The distortion is spread over large part of the spectrum so to reveal it one can use a detector with relatively poor (near 10-15%) energy resolution. A classic proportional counter is a simple natural choice for a tritium $\\beta$-decay detector. The method we are proposing is original in two respects. First, the counter is produced as a whole from fully-fused quartz tube allowing to measure current pulse directly from anode while providing high stability for a long time. Second, a modern digital acquisition technique can be used in measurements at ultrahigh count rate - up to 10$^6$ Hz. As a result an energy spectrum of tritium electrons containing up to 10$^{12}$ counts may be collected in a month of live time measurements. Due to high statistics an upper limit down to 10$^{-3}$..10$^{-5}$ ca...

The search for alternatives to PMTs as photosensors in optical TPCs for rare event detection has significantly increased in the last few years. In particular, in view of the next generation large volume detectors, the use of photosensors with lower natural radioactivity, such as large area APDs or GM-APDs, with the additional possibility of sparse surface coverage, triggered the intense study of secondary scintillation production in micropattern electron multipliers, such as GEMs and THGEMs, as alternatives to the commonly used uniform electric field region between two parallel meshes. The much higher scintillation output obtained from the electron avalanches in such microstructures presents an advantage in those situations. The accurate knowledge of the amount of such scintillation is important for correct detector simulation and optimization. It will also serve as a benchmark for software tools developed and/or under development for the calculation of the amount of such scintillation. The secondary scintillation yield, or electroluminescence yield, in the electron avalanches of GEMs and THGEMs operating in gaseous xenon and argon has been determined for different gas pressures. At 1 bar, THGEMs deliver electroluminescence yields that are more than one order of magnitude higher when compared to those achieved in GEMs and two orders of magnitude when compared to those achieved in a uniform field gap. The THGEM electroluminescence yield presents a faster decrease with pressure when comparing to the GEM electroluminescence yield, reaching similar values to what is achieved in GEMs for xenon pressures of 2.5 bar, but still one order of magnitude higher than that produced in a uniform field gap. Another exception is the GEM operating in argon, which presents an electroluminescence yield similar to that produced in a uniform electric field gap, while the THGEM achieves yields that are more than one order of magnitude higher.

Energies, transition rates, and electron electric dipole moment (EDM) enhancement factors are calculated for low-lying states of Ce IV and Pr V using relativistic many-body perturbation theory. This study is related to recent investigations of the more complicated Gd IV ion, which is promising for electronEDM experiments. The ions Ce IV and Pr V both have a single valence electron, permitting one to carry out reliable ab-initio calculations of energy levels, transition rate...

Full text: One of the most important experiments in particle physics is the hunt for an EDM of a neutron. To achieve sensitivities to EDMs of a few times 10-28 e.cm, the magnetic field, including its spatial gradients, has to be precisely measured and controlled. To provide the required sensitivity of magnetic field measurements at the <100fT/?(Hz) level, a system of optically-pumped atomic Cs magnetometers has been developed at Fribourg University. The Cs sensor itself is a spherical, paraffin-coated and evacuated glass cell containing Cs vapour at room temperature. The present magnetometer system consists of 8 vacuum compatible and four vacuum and high voltage compatible sensors. The system is in constant evolution to adapt it to the operating environment of the nEDM experiment at the Paul Scherrer Institut. In this contribution, the current solutions and results of magnetic field measurements will be presented. (author)

In the present work the effect of different dielectric mediums in micro-EDM of ?-Titanium Aluminide alloy have been investigated. Experiments were conducted both in the absence (dry conditions) and in presence of dielectric (EDM oil).Circular craters were produced both in the presence and absence of dielectric fluid using varying micro-EDM process variables i.e. open circuit voltage, discharge capacitance, pulse frequency and pulse-on-time. Over cut was measured from optical microscope images using Image Analyzer software. Influences of process variables and optimal conditions for minimum over cut on crater dimensions were investigated. ANOVA test which shows that capacitance of RC circuit contributes significantly in crater formation followed by pulse frequency. Optical photographs exhibit that over cut are less in air medium compared to oil medium.

The surface morphology, surface roughness and micro-crack of AISI D2 tool steel machined by the electrical discharge machining (EDM) process were analyzed by means of the atomic force microscopy (AFM) technique. Experimental results indicate that the surface texture after EDM is determined by the discharge energy during processing. An excellent machined finish can be obtained by setting the machine parameters at a low pulse energy. The surface roughness and the depth of the micro-cracks were proportional to the power input. Furthermore, the AFM application yielded information about the depth of the micro-cracks is particularly important in the post treatment of AISI D2 tool steel machined by EDM

In the present work the effect of different dielectric mediums in micro-EDM of ?-Titanium Aluminide alloy have been investigated. Experiments were conducted both in the absence (dry conditions) and in presence of dielectric (EDM oil).Circular craters were produced both in the presence and absence of dielectric fluid using varying micro-EDM process variables i.e. open circuit voltage, discharge capacitance, pulse frequency and pulse-on-time. Over cut was measured from optical microscope images using Image Analyzer software. Influences of process variables and optimal conditions for minimum over cut on crater dimensions were investigated. ANOVA test which shows that capacitance of RC circuit contributes significantly in crater formation followed by pulse frequency. Optical photographs exhibit that over cut are less in air medium compared to oil medium.

In this paper, a new method of material processing is treated, which is the broaching of deep holes with a variety of diameters and shapes uniformly by electrical discharges machining (EDM). The experimental results of surface structure after EDM is shown. (author)

The 5th International Conference on Educational Data Mining (EDM 2012) is held in picturesque Chania on the beautiful Crete island in Greece, under the auspices of the International Educational Data Mining Society (IEDMS). The EDM 2012 conference is a leading international forum for high quality research that mines large data sets of educational…

The Second International Conference on Educational Data Mining (EDM2009) was held at the University of Cordoba, Spain, on July 1-3, 2009. EDM brings together researchers from computer science, education, psychology, psychometrics, and statistics to analyze large data sets to answer educational research questions. The increase in instrumented…

The Third International Conference on Data Mining (EDM 2010) was held in Pittsburgh, PA, USA. It follows the second conference at the University of Cordoba, Spain, on July 1-3, 2009 and the first edition of the conference held in Montreal in 2008, and a series of workshops within the AAAI, AIED, EC-TEL, ICALT, ITS, and UM conferences. EDM 2011…

The understanding of physical and chemical processes in the interstellar medium is currently an important challenge for our Universe knowledge since these processes are involved in the control of stars and planets formation. Polycyclic Aromatic Hydrocarbons (PAHs) are now recognized as an important constituent of the interstellar medium gaseous phase, mainly through observations of their IR emission bands. This family of molecules and in particular their ionic and radical derivatives seems to be one of the most promising candidates for the identification of the Diffuse Interstellar Bands (DIBs). These absorption bands, observed - throughout the visible and near infrared spectral range - over spectra of stars masked by gas cloud, were first discovered in 1922. Their spectral properties indicate that DIBs could originate from gaseous phase carbonaceous molecules. The identification of PAHs as molecules responsible for these bands must be done through direct comparison with PAHs spectra recorded in conditions as close as possible to those of the interstellar medium. An exhaustive survey of all the literature spectra of the PAHs in the neutral or ionic (cation and anion) forms was achieved and will be reported here, allowing us to find some trends among the PAH spectra: for instance, concerning the band shift due to the interaction with the matrix; concerning the distribution of transitions of a large amount of PAH cations, through their PhotoElectron Spectra (N. Boudin, R. Ruiterkamp and B. H. Foing, A&A, 2003). The advantages and drawbacks of all the experimental techniques (PhotoElectron Spectroscopy, Matrix Isolation Spectroscopy, gas phase techniques) will be discussed. Concurrently, this large database allow us to search these laboratory transitions in the astronomical spectra already published. A follow up interdisciplinary work is required between astronomical observations, laboratory matrix and gas phase spectroscopy, theoretical work and modelling, and active experiments in space to study the formation, evolution, survival and transport of these complex organics.

A new method for the detection of the electronedm using a solid is described. The method involves the measurement of a voltage induced across the solid by the alignment of the samples magnetic dipoles in an applied magnetic field, H. A first application of the method to GdIG has resulted in a limit on the electronedm of 5E-24 e-cm, which is a factor of 40 below the limit obtained from the only previous solid-state edm experiment. The result is limited by the imperfect discrimination of an unexpectedly large voltage that is even upon the reversal of the sample magnetization.

CP violating electron-nucleon interactions and the resulting atomic EDM are studied in several models. In the standard model these interactions are very small and are well below the experimental upper bounds. In multi-Higgs doublet models. The four-Fermi interactions, anti NNanti e?5e and anti N?5Nanti ee, can be quite large. In some range of parameters the contribution of these interactions to the atomic EDM can exceed the contribution of the electronEDM. In leptoquark models the contribution from the tensor interaction, anti N???Nanti e????5e, is the dominant one in Hg, Xe and TlF. (orig.)

Full Text Available É sabido que a Usinagem por Descargas Elétricas (EDM é um processo térmico em que pode haver temperaturas muito elevadas (superiores a 1.200°C na região de usinagem. Consequentemente é fácil de entender o fato de as peças usinadas por EDM apresentarem camadas superficiais endurecidas, refundidas e com elevado número de microtrincas superficiais. A formação de microtrincas está associada com o desenvolvimento de altas tensões térmicas que excedem a tensão máxima de resistência do material. Além disso, as microtrincas superficiais penetram em profundidade com extensões que dependem da energia de descarga. O trabalho proposto tem por objetivo estudar o efeito da adição de pó de SiC em vários fluidos dielétricos, sobre a geração de microtrincas superficiais, no aço rápido ABNT M2, durante a usinagem por descargas elétricas. Os resultados apresentados mostramredução da quantidade de microtrincas nas superfícies usinadas, quando se adiciona pó de SiC ao dielétrico, quando comparadas com as usinadas com EDM convencional.It is known that Electrical Discharge Machining (EDM is a thermal process in which extremely high temperatures (in excess of 1200°C can occur in the machining area. Consequently, it is easy tounderstand that during each electric discharge, high temperatures are generated, causing local fusion or even evaporation of the machined material. In each discharge, a crater is formed in the material and a small crater is formed in the electrode. Of every meltedmaterial produced in each discharge, only 15% or less is removed using dielectric fluid. The remaining melted material solidifies, forming a wrinkled surface. The characteristics of theobtained surface – overlap of craters, globules of sullage, chimneys, bubbles (formed when the gases arrested are liberated through the resolidified material – are revealed through an analysis using a scanning electron microscope. The proposed work has as its objective to study the effect of the addition of SiC powder into several dielectric fluids, on microcrack formation of high-speed steel (ABNT M2, during electrical discharge machining. The results show that the samples machined with the addition of SiC powders presentedsignificant reduction in the number of microcracks in the machined surface, when compared with those machined with conventional EDM.

Full Text Available As the number of electronic serials available to libraries continues to increase while library budgets remain either stagnant or on the decrease, it becomes necessary to evaluate the use of a library’s electronic collection. In 2006, usage statistics were evaluated at Laurentian University, Canada, to provide direction to collection development and identify high-cost low-use electronic serials. Searches and full-text downloads were studied. A sharp increase in use was observed in and around 2004 which can be explained by the introduction, in Ontario, of the ‘double cohort’, by the rapid increase in the number of electronic resources subscribed to at Laurentian, and by the adoption of OpenURL technology. Heavily used electronic serials are identified. Turnaways, connections by IP address and Bradford’s 20:80 rule are also examined. The application of a cost-per-download ratio provided a practical method for identifying underused products.

We consider theories where lepton flavor is violated, in particular concentrating on the four fermion operator consisting of three electrons and a tau. Strong constraints are available from existing searches for tau -> eee, requiring the scale of the contact interaction to be less than ~(9 TeV)^-2. We reexamine this type of physics, assuming that the particles responsible are heavy (with masses greater than ~TeV) such that a contact interaction description continues to be applicable at the energies for a future e+e- collider. We find that the process e+e- -> e tau can be a very sensitive probe of this kind of physics (even for very conservative assumptions about the detector performance), already improving upon the tau decay bounds to less than ~(11 TeV)^-2 at collider energy sqrt(s) 500 GeV, or reaching beyond ~(35 TeV)^-2 for sqrt(s) = 3 TeV. Even stronger bounds are possible at e-e- colliders in the same energy range.

In 1985 Simpson reported evidence for the emission of a 17 keV mass neutrino in a small fraction of tritium beta decays. An experimental controversy ensued in which a number of both positive and negative results were reported. The beta spectrum of 14C was collected in a unique 14C-doped planar germanium detector and a distortion was observed that initially confirmed Simpson's result. Further tests linked this distortion to a splitting of the collected charge between the central detector and the surrounding guard ring in a fraction of the events. A second 14C measurement showed no evidence for emission of a 17 keV mass neutrino. In a related experiment, a high statistics electron-capture internal-bremsstrahlung photon spectrum of 55Fe was collected with a coaxial germanium detector. A local search for departures from a smooth shape near the endpoint was performed, using a second-derivative technique. An upper limit of 0.65% (95% C.L.) for the mixing Of a neutrino in the mass range 5--25 keV was established. The upper limit on the mixing of a 17 keV mass neutrino was 0.14% (95% C.L.)

In a recent paper [A. O. Sushkov, S. Eckel and S. K. Lamoreaux, Phys. Rev. A 79, 022118 (2009), arXiv:0810.2756 ] the authors measured the EDM-induced magnetization M that is given by Eq. (1) in their paper. Such an expression for M is a consequence of the generally accepted opinion that both dipole moments, a MDM m and an EDM d, are proportional to the spin S. Recently [T. Ivezic, Phys. Scr. 81, 025001 (2010)] the Uhlenbeck-Goudsmit hypothesis is generalized in a Lorentz covariant manner using the four-dimensional (4D) geometric quantities. From the viewpoint of such formulation there is no EDM-induced magnetization M; in the 4D spacetime the EDM d^{a} is not proportional to S^{a}. It is argued that the induced M can come from the direct interaction between the applied electric field E^{a} and a MDM m^{a}.

The Standard Model (SM) of Particle Physics predicts a permanent electric dipole moment for the neutron (nEDM), breaking time reversal and parity symmetry. The electroweak prediction is several orders of magnitude below the current best experimental limit dn-26ecm (90 % CL, ILL-RAL-Sussex). Many SM extensions predict a nEDM in the range of current experimental sensitivity. Improving the upper experimental limit restricts the allowed parameter space of these models. In a first step the nEDM collaboration has installed the upgraded ILL-RAL-Sussex instrument at the new ultra-cold neutron (UCN) source at the Paul Scherrer Institut (PSI), Switzerland. The collaboration aims at increasing the experimental sensitivity by a factor of five due to the expected higher UCN density and improved control of systematic effects. In parallel a new apparatus is developed for a next measurement phase aiming at another order of magnitude improvement. The experiment employs the Ramsey method of separated oscillatory fields to detect a shift of the Larmor precession frequency of UCN in a parallel and an anti-parallel configuration of very homogeneous magnetic and electric fields. In 2010/2011, the nEDM apparatus has been characterized in detail. The polarized UCN infrastructure was studied and significant progress in the homogeneity of the magnetic field was achieved. Preliminary results of dedicated measurements related to the major systematic false effects are presented.

The nEDM collaboration is developing a new experiment to measure the neutron's electric dipole moment to ˜10-28 e--cm. A non-zero neutron EDM would be the first observation of CP violation in a baryon containing only light quarks, while a null result would be inconsistent with predictions from most variants of supersymmetry. The experiment will measure the difference in spin precession, of polarized ultracold neutrons (UCN) produced and stored in a superfluid-helium-filled cell, when the magnetic and electric fields are parallel and antiparallel. A key feature of the experimental method is the use of polarized ^3He atoms within the cell acting as both spin analyzer and comagnetometer to the UCN. In one mode of running, the ^3He precession signal is detected by SQUID gradiometers adjacent to the cell. This talk will cover the efforts of the nEDM collaboration towards practical implementation of SQUIDs for the ^3He comagnetometer readout, with a goal of <=1 fT/?Hz noise level (referred to one gradiometer loop), low enough to be a small contribution to the overall uncertainty of the final nEDM result. )

Titanium alloys which are categorized as lightweight materials, poses greater strength and toughness are usually known to create major challenges during machining. Electrical discharge machining (EDM) which is very prominent amongst the non-conventional machining methods is expected to be used quite extensively in machining titanium alloys. EDM process is known to cause surface damaged layers which consists of three types of surfaces; spattered, recast and heat affected zone. This project was undertaken to study the machining performance of EDM and powder mixed dielectric-electrical discharge machining (PMDEDM) in machining Ti-6246 with respect to the surface integrity of machined surface by using copper tungsten (CuW) electrode. The machining parameters considered are voltage (V), current (I), pulse on time(Ton), interval time (Toff) and concentration of the SiC powder (C) in dielectric fluid. The respected responses investigated include surface alteration and overcut. It was found that PMD-EDM process produced less damaging effect on the surface layer of the machined surface and widened the overcut. (author)

Full Text Available Optimization is one of the techniques used in manufacturing sectors to arrive for the best manufacturing conditions, which is an essential need for industries towards manufacturing of quality products at lower cost. This paper aims to investigate the optimal set of process parameters such as current, pulse ON and OFF time in Electrical Discharge Machining (EDM process to identify the variations in three performance characteristics such as rate of material removal, wear rate on tool, and surface roughness value on the work material for machining Mild Steel IS 2026 using copper electrode. Based on the experiments conducted on L9 orthogonal array, analysis has been carried out using Grey Relational Analysis, a Taguchi method. Response tables and graphs were used to find the optimal levels of parameters in EDM process. The confirmation experiments were carried out to validate the optimal results. Thus, the machining parameters for EDM were optimized for achieving the combined objectives of higher rate of material removal, lower wear rate on tool, and lower surface roughness value on the work material considered in this work. The obtained results show that the Taguchi Grey relational Analysis is being effective technique to optimize the machining parameters for EDM process.

The present study performs the small area electro-discharge machining (EDM) process with a low wear-rate copper-tungsten electrode of diameter 1.5 mm to establish the influence of the EDM parameters on various aspects of the surface integrity of AISI 1045 carbon steel. The residual stress induced by the EDM process is measured using the Hole-Drilling Strain-Gage Method. The experimental results reveal that the values of material removal rate (MRR), surface roughness (SR), hole enlargement (HE), average white layer thickness (WLT), and induced residual stress tend to increase at higher values of pulse current and pulse-on duration. However, for an extended pulse-on duration, it is noted that the MRR, SR, and surface crack density all decrease. Furthermore, the results indicate that obvious cracks are always evident in thicker white layers. A smaller pulse current (i.e. 1 A) tends to increase the surface crack density, while a prolonged pulse-on duration (i.e. 23 ?s) widens the opening degree of the surface crack, thereby reducing the surface crack density. The EDM hole drilling process induces a compressive residual stress within the workpiece. A linear relationship is identified between the maximum residual stress and the average white layer thickness. It is determined that the residual stress can be controlled effectively by specifying an appropriate pulse-on duration

The safety and environmental aspects of a manufacturing process are important due to increased environmental regulations and life quality. In this paper, the concentration of aerosols in the breathing zone of the operator of Electrical Discharge Machining (EDM), a commonly used non traditional manufacturing process is presented. The pattern of aerosol emissions from this process with varying process parameters such as peak current, pulse duration, dielectric flushing pressure and the level of dielectric was evaluated. Further, the HAZOP technique was employed to identify the inherent safety aspects and fire risk of the EDM process under different working conditions. The analysis of aerosol exposure showed that the concentration of aerosol was increased with increase in the peak current, pulse duration and dielectric level and was decreased with increase in the flushing pressure. It was also found that at higher values of peak current (7A) and pulse duration (520 micros), the concentration of aerosols at breathing zone of the operator was above the permissible exposure limit value for respirable particulates (5 mg/m(3)). HAZOP study of the EDM process showed that this process is vulnerable to fire and explosion hazards. A detailed discussion on preventing the fire and explosion hazard is presented in this paper. The emission and risk of fire of the EDM process can be minimized by selecting proper process parameters and employing appropriate control strategy. PMID:20720340

The correct selection of manufacturing conditions is one of the most important aspects to take into consideration in the majority of manufacturing processes and, particularly, in processes related to Electrical Discharge Machining (EDM). It is a capable of machining geometrically complex or hard material components, that are precise and difficult-to-machine such as heat treated tool steels, composites, super alloys, ceramics, carbides, ...

In this paper, the effect of surface-active substance (SAS) additional in working liquid on the solid surface erosion process by EDM is treated. The experimental data of dispersion particles distribution depending on additional concentration of SAS are shown. (author)

Inconel alloys including IN 718 alloy are widely used in turbomachinery industry due to their superior mechanical properties. Inconel alloys are very difficult to machine using cutting and grinding. Wire electrical discharge machining (W-EDM) is an alternative process to manufacture complex Inconel parts. However, little research has been done on surface integrity by W-EDMed IN 718. This study focuses on surface integrity of IN 718 by W-EDM at different modes of discharge energy. The results show that the EDMed surface topography shows dominant coral reef microstructures at high energy mode, while random microvoids are dominant at low energy modes. The average roughness can be significantly reduced at low energy mode. A thick white layer is predominantly discontinuous and non-uniform at relative high energy modes. Microvoids are confined within the thick white layers and no microcracks were found in the subsurface. A thin white layer by trim cut at low energy mode becomes continuous, uniform, and is free of voids. Compared to the bulk, white layers have dramatic reduction in microhardness. In addition, surface alloying from wire electrode and water dielectric is obvious in main cut, but it can be minimized in trim cuts.

Wire-EDM has recently shown itself as an alternative approach for slicing silicon and other semiconductor materials without the presence of significant chipping as normally found in the traditional machining processes. However, the intensive electrical spark between a wire electrode and silicon can cause damage to the cut surface and subsurface in micro and nano-scale aspects. This paper presents the influence of major process parameters on the cut surface characteristics and damage in the wire-EDMing of silicon. An n-type monocrystalline silicon wafer was cut under different spark energy densities, duty cycles and dielectric flushing rates. Poor cut surface quality and high amount of electrode material deposition were obtained when low spark energy density, small duty cycle and low dielectric flushing rate were applied. Moreover, the amorphous and defective crystal structures of silicon were apparent under the low spark energy condition. The interactions between the wire-EDMing parameters and cut surface characteristics drawn in this study could have significances for the further development of EDM technology towards the fine-scale and damage-free processing of semiconductor materials.

Full Text Available In this paper the complexity of electrical discharge machining process which is very difficult to determine optimal cutting parameters for improving cutting performance has been reported. Optimization of operating parameters is an important step in machining, particularly for operating unconventional machiningprocedure like EDM. A suitable selection of machining parameters for the electrical discharge machining process relies heavily on the operators’ technologies and experience because of their numerous and diverse range. Machining parameters tables provided by the machine tool builder can not meet the operators’ requirements, since for anarbitrary desired machining time for a particular job, they do not provide the optimal machining conditions. An approach to determine parameters setting is proposed. Based on the Taguchi parameter design method and the analysis of variance, the significant factors affecting the machining performance such as total machining time, oversize and taper for a hole machined by EDM process, are determined.Artificial neural networks are highly flexible modeling tools with an ability to learn the mapping between input variables and output feature spaces. The superiority of using artificial neural networks inmodeling machining processes make easier to model the EDM process with dimensional input and output spaces. On the basis of the developed neural network model, for a required total machining time, oversize and taper the corresponding process parameters to be set in EDM by using the developed and trained ANN are determined.

Electron diffusion in a liquid xenon time projection chamber has recently been used to infer the z coordinate of a particle interaction, from the width of the electron signal. The goal of this technique is to reduce the background event rate by discriminating edge events from bulk events. Analyses of dark matter search data which employ it would benefit from increased longitudinal electron diffusion. We show that a significant increase is expected if the applied electric field is decreased. This observation is trivial to implement but runs contrary to conventional wisdom and practice. We also extract a first measurement of the longitudinal diffusion coefficient, and confirm the expectation that electron diffusion in liquid xenon is highly anisotropic under typical operating conditions.

Electron diffusion in a liquid xenon time projection chamber has recently been used to infer the $z$ coordinate of a particle interaction, from the width of the electron signal. The goal of this technique is to reduce the background event rate by discriminating edge events from bulk events. Analyses of dark matter search data which employ it would benefit from increased longitudinal electron diffusion. We show that a significant increase is expected if the applied electric field is decreased. This observation is trivial to implement but runs contrary to conventional wisdom and practice. We also extract a first measurement of the longitudinal diffusion coefficient, and confirm the expectation that electron diffusion in liquid xenon is highly anisotropic under typical operating conditions.

The ATLAS detector at the Large Hadron Collider is used to search for excited electrons and excited muons in the channel pp ? ??* ? ???, assuming that excited leptons are produced via contact interactions. The analysis is based on 13 fb?1 of pp collisions at a centre-of-mass energy of 8 TeV. No evidence for excited leptons is found, and a limit is set at the 95% credibility level on the cross section times branching ratio as a function of the excited-lepton mass m?*. For m?* ? 0.8 TeV, the respective upper limits on ?B(?* ? ??) are 0.75 and 0.90 fb for the e* and ?* searches. Limits on ?B are converted into lower bounds on the compositeness scale ?. In the special case where ? = m?*, excited-electron and excited-muon masses below 2.2 TeV are excluded. (paper)

The application of advanced theory and modeling techniques has become an essential component to understand material properties and hasten the design and discovery of new ones. This is true for diverse applications. Therefore, current efforts aimed towards finding new scintillator materials are also aligned with this general predictive approach. The need for large scale deployment of efficient radiation detectors requires discovery and development of high-performance, yet low-cost, scintillators. While Tl-doped NaI and CsI are still some of the widely used scintillators, there are promising new developments, for example, Eu-doped SrI2 and Ce-doped LaBr3. The newer candidates have excellent light yield and good energy resolution, but challenges persist in the growth of large single crystals. We will discuss a theoretical basis for anticipating improved proportionality as well as light yield in solid solutions of certain systems, particularly alkali iodides, based on considerations of hot-electron group velocity and thermalization. Solid solutions based on NaI and similar alkali halides are attractive to consider in more detail because the end point compositions are inexpensive and easy to grow. If some of this quality can be preserved while reaping improved light yield and possibly improved proportionality of the mixture, the goal of better performance at the low price of NaI:Tl might be attainable by such a route. Within this context, we will discuss a density functional theory (DFT) based study of two prototype systems: mixed anion NaIxBr1-x and mixed cation NaxK1-xI. Results obtained from these two prototype candidates will lead to further targeted theoretical and experimental search and discovery of new scintillator hosts.

Sinking type electro discharge machine (EDM) is the nwst popular non conventional machining method in the current decade based on modern CNC controlled. Although the EDM process has been used for decades, it is still widely misunderstood by many in manufacturing. The EDM is used when the work piece material is too hard, or the shape or location of the detail cannot easily be conventionally machined e.g. high precision mold and die with high surface quality. The performance of this process can...

The Standard Model (SM) of particle physics is known to be incomplete. It fails to explain dark matter, and why matter survived annihilation with antimatter following the Big Bang. Proposed extensions to the SM, such as weak-scale Supersymmetry (SUSY), may explain these phenomena by positing the existence of new particles and new interactions that are not symmetric under the time-reversal (T) transformation. These same theories nearly always predict a small, yet potentially measurable, asymmetric charge distribution directed along the spin ($\\vec{S}$) of the electron, an electric dipole moment (EDM, $\\vec{d_e}=d_e \\vec{S}/(\\hbar/2)$), which is also asymmetric under T. The predicted value of $d_e$ in these SM extensions is typically in the range of $10^{-27}$-$10^{-30}$ $e$ cm, orders of magnitude larger than is predicted by the SM. Here, we report a new search for the electronEDM using the polar molecule thorium monoxide (ThO). Our result, $d_e = (-2.1 \\pm 3.7_\\mathrm{stat} \\pm 2.5_\\mathrm{syst})\\times 10^{-...

We describe an experiment to search for a new vector boson A(prime) with weak coupling ?(prime) > 6 x 10-8 ? to electrons (? = e2/4?) in the mass range 65 MeV A#prime# +e- spectrum. We summarize the experimental approach described in a proposal submitted to Jefferson Laboratory's PAC35, PR-10-009. This experiment, the A(prime) Experiment (APEX), uses the electron beam of the Continuous Electron Beam Accelerator Facility at Jefferson Laboratory (CEBAF) at energies of ?1-4 GeV incident on 0.5-10% radiation length Tungsten wire mesh targets, and measures the resulting e+e- pairs to search for the A(prime) using the High Resolution Spectrometer and the septum magnet in Hall A. With a ?1 month run, APEX will achieve very good sensitivity because the statistics of e+e- pairs will be ?10,000 times larger in the explored mass range than any previous search for the A(prime) boson. These statistics and the excellent mass resolution of the spectrometers allow sensitivity to ?(prime)/? one to three orders of magnitude below current limits, in a region of parameter space of great theoretical and phenomenological interest. Similar experiments could also be performed at other facilities, such as the Mainz Microtron.

In the paper being commented on it is proposed a new method for the detection of the electronEDM using the solid GdIG. There, it is argued that a sample electric polarization appears when the sample is magnetized; the common belief is that the electronEDM must be collinear with its magnetic moment. All this is objected and it is suggested that the polarization of the sample can be explained by the direct, Lorentz covariant, interaction between B^{a} and an EDM d^{a}.

This book contains information about the resources available to merge new technology and the search for employment. It offers suggestions from human resource specialists, software authors, and database experts. Chapter 1 is an overview of how the computer has become indispensable in a job search. Chapter 2 focuses on external, third-party resume…

In this research, the inner surface characteristics of micro-drilled holes of fuel injector nozzles were analyzed by Shear Force Microscopy (SHFM). The surface texture was characterized by maximum peak-to-valley distance and periodicity whose dimensions were related to the adopted energy. 180 µm diameter holes were drilled using ultrashort pulsed laser process using pulse energies within the range of 10-50 µJ. Laser ablated surfaces in the tested energy range offer a smooth texture with a peculiar periodic structure with a variation in height between 60 and 90 nm and almost constant periodicity. The Scanning Electron Microscopy (SEM) photograph of the Laser Induced Periodic Surface Structure (LIPSS) showed the co-existence of Low Spatial Frequency LIPSS (LSFL) and High Spatial Frequency LIPSS (HSFL). A comparative analysis was carried out between the highest laser pulse energy in the tested range energy laser drilling which enables the shortest machining time and micro-Electrical Discharge Machining (µ-EDM). On the contrary, results showed that surfaces obtained by electro-erosion are characterized by a random distribution of craters with a total excursion up to 1.5 µm with a periodicity of 10 µm. The mean-squared surface roughness (Rq) derived from the scanned maps ranges between 220 and 560 nm for µ-EDM, and between 50 and 100 nm for fs-pulses laser drilling.

We present the results of a search for the production of an excited state of the electron, e*, in proton-antiproton collisions at $\\sqrt{s}$ = 1.96 TeV. The data were collected with the D0 experiment at the Fermilab Tevatron Collider and correspond to an integrated luminosity of approximately 1 fb^-1. We search for e* in the process ppbar -> e* e, with the e* subsequently decaying to an electron plus photon. No excess above the standard model background is observed. Interpreting our data in the context of a model that describes e* production by four-fermion contact interactions and e* decay via electroweak processes, we set 95% C.L. upper limits on the production cross section ranging from 8.9 fb to 27 fb, depending on the mass of the excited electron. Choosing the scale for contact interactions to be Lambda = 1 TeV, excited electron masses below 756 GeV are excluded at the 95% C.L.

A search for a resonant state coupled to an electron-quark pair has been performed using collisions of the electron beam of 26.7 GeV and the proton beam of 820 GeV. With the integrated luminosity of 26.6 ± 1.6 nb-1, scalar and vector leptoquarks have been searched for in the neutral current and charged current samples. The selected events agreed well with the prediction of the Standard Model, and no evidence has been found for production of leptoquarks decaying into e- + jet or ? + jet. Limits on the coupling strength of scalar (vector) leptoquarks to electron and quark have been determined for masses from 50 (40) GeV to 225 GeV. A limit on the leptoquark mass has been also obtained at the 95% confidence level assuming that either left-handed or right-handed coupling exists to the electron-quark pair with electroweak strength. The mass limit depends on the cross section determined by the choice of quantum numbers. Leptoquarks are ruled out for masses below 216 GeV with the largest cross section and below 105 GeV with the smallest cross section. (author) 102 refs

Trapped diatomic molecular ions could prove to be a sensitive probe for a permanent electron electric dipole moment (eEDM). We propose to use a ground or metastable $^3\\Delta_1$ level, due to its high polarizability and large EDM enhancement factor. Ions allow for simple trapping and long interrogation times, but require a time-varying electric bias field in order to probe the eEDM. We discuss experimental design as well as challenges in performing a precision spectroscopic measurement in rapidly time-varying electric fields.

Full Text Available while library budgets remain either stagnant or on the decrease, it becomesnecessary to evaluate the use of a library's electronic collection. In 2006, usagestatistics were evaluated at Laurentian University, Canada, to provide direction tocollection development and identify high-cost low-use electronic serials.Searches and full-text downloads were studied. A sharp increase in use wasobserved in and around 2004 which can be explained by the introduction, inOntario, of the 'double cohort', by the rapid increase in the number of electronicresources subscribed to at Laurentian, and by the adoption of OpenURLtechnology. Heavily used electronic serials are identified. Turnaways,connections by IP address and Bradford's 20:80 rule are also examined. Theapplication of a cost-per-download ratio provided a practical method foridentifying underused products.

Electrical Discharge Machining (EDM) is a non conventional machining process, where electrically conductive materials are machined by using a precisely controlled spark that occurs between an electrode and a work piece in the presence of a dielectric fluid. It has been a demanding research area to model and optimize the EDM process in the present scenario. In this work a neural network model is presented for predictions of material removal rate (MRR) & tool wear rate (TWR) in die sinking elec...

EDM machining is used for very hard and complex cutting of conducting materials with higher surface finish and close dimensions. EDM process parameters are affected by both electrical and non electrical parameters. In these paper cutting of hard material high carbon high chromium (HCHcr) D3 steel is done on electro discharge machine with copper as cutting tool electrode. This paper presents a work on the performance parameter optimization for material removal rate (MRR) and electrode wear rat...

Abstract: We describe an experiment to search for a new vector boson A' with weak coupling alpha' > 6 x 10^{-8} alpha to electrons (alpha=e^2/4pi) in the mass range 65 MeV < m_A' < 550 MeV. New vector bosons with such small couplings arise naturally from a small kinetic mixing of the "dark photon" A' with the photon -- one of the very few ways in which new forces can couple to the Standard Model -- and have received considerable attention as an explanation of various dark matter related anomalies. A' bosons are produced by radiation off an electron beam, and could appear as narrow resonances with small production cross-section in the trident e+e- spectrum. We summarize the experimental approach described in a proposal submitted to Jefferson Laboratory's PAC35, PR-10-009. This experiment, the A' Experiment (APEX), uses the electron beam of the Continuous Electron Beam Accelerator Facility at Jefferson Laboratory (CEBAF) at energies of ~1-4 GeV incident on 0.5-10% radiation length Tungsten wire mesh targets, and measures the resulting e+e- pairs to search for the A' using the High Resolution Spectrometer and the septum magnet in Hall A. With a ~1 month run, APEX will achieve very good sensitivity because the statistics of e+e- pairs will be ~10,000 times larger in the explored mass range than any previous search for the A' boson. These statistics and the excellent mass resolution of the spectrometers allow sensitivity to alpha'/alpha one to three orders of magnitude below current limits, in a region of parameter space of great theoretical and phenomenological interest. Similar experiments could also be performed at other facilities, such as the Mainz Microtron.

An out-of-plane motion of spin in the resonant EDM experiment (Y.F. Orlov, Proc. of STORI'05, p. 223; Y.K. Semertzidis, ibid., p. 70) is affected by electric and magnetic fields. The effect of a resonant electric field is significant, while the contribution from a magnetic field caused by an oscillating part of particle velocity is dominant. The amplitude of effective field defining the resonant effect has been found. The effect of electric field on the spin dynamics has not been taken into account in previous works. This effect is considerable and leads to decreasing the EDM effect for the deuteron and increasing it for the proton. The spin dynamics has been calculated.

We propose a new technique for the determination and monitoring of the interior vector magnetic field components during the operation of neutron EDM experiments. If a suitable three-dimensional volume surrounding the fiducial volume of an experiment can be defined which contains no interior currents or magnetization, each of the interior vector field components will satisfy the Laplace Equation within this volume. Therefore, if the field components can be measured on the boundary, the interior vector field components can be determined uniquely via numerical solution of the Laplace Equation. We discuss the applicability of this technique to the determination of the magnetic field components and magnetic field gradients in the fiducial volumes of neutron EDM experiments.

The purpose of this study was to develop the on-machine measurement techniques so as to precisely fabricate micro intricate part using ultra-fine w-EDM. The measurement-assisted approach which employs an automatic optical inspection (AOI) is incorporated to ultra-fine w-EDM process to on-machine detect the machining error for next re-machining. The AOI acquires the image through a high resolution CCD device from the contour of the workpiece after roughing in order to further process and recognize the image for determining the residual. This facilitates the on-machine error detection and compensation re-machining. The micro workpiece and electrode are not repositioned during machining. A fabrication for a micro probe of 30-?m diameter is rapidly machined and verified successfully. Based on the proposed technique, on-machine measurement with AOI has been realized satisfactorily.

A post-cast EDM process is used to remove material from the interior surface of a nozzle vane cavity of a turbine. A thin electrode is passed through the cavity between opposite ends of the nozzle vane and displaced along the interior nozzle wall to remove the material along a predetermined path, thus reducing the thickness of the wall between the cavity and the external surface of the nozzle. In another form, an EDM process employing a profile as an electrode is disposed in the cavity and advanced against the wall to remove material from the wall until the final wall thickness is achieved, with the interior wall surface being complementary to the profile surface.

The purpose of this study was to develop the on-machine measurement techniques so as to precisely fabricate micro intricate part using ultra-fine w-EDM. The measurement-assisted approach which employs an automatic optical inspection (AOI) is incorporated to ultra-fine w-EDM process to on-machine detect the machining error for next re-machining. The AOI acquires the image through a high resolution CCD device from the contour of the workpiece after roughing in order to further process and recognize the image for determining the residual. This facilitates the on-machine error detection and compensation re-machining. The micro workpiece and electrode are not repositioned during machining. A fabrication for a micro probe of 30-?m diameter is rapidly machined and verified successfully. Based on the proposed technique, on-machine measurement with AOI has been realized satisfactorily.

Europeana aims to bring together metadata for cultural heritage objects from institutions throughout Europe, to increase their visibility and accessibility. This project requires that metadata created and stored in a multitude of different formats and variations to be normalized into a single, standard format, which is soon to be EDM. This constitutes a massive effort on the part of institutions and aggregators, and any system that can ease the process of converting millions of metadata recor...

In this paper the complexity of electrical discharge machining process which is very difficult to determine optimal cutting parameters for improving cutting performance has been reported. Optimization of operating parameters is an important step in machining, particularly for operating unconventional machiningprocedure like EDM. A suitable selection of machining parameters for the electrical discharge machining process relies heavily on the operators’ technologies and experience because of ...

Electrical discharge machining (EDM) has been recognized as an efficient production method for precision machining of electrically conducting hardened materials. Copper and aluminium are used as electrode materials in this process with Kerosene oil as the dielectric medium. In this work, the behavior of copper and aluminium electrodes on electric discharge machining of EN-8 alloy steel had been studied. Keeping all other machining parameters same, the hardened work material was machined with ...

Optimization is one of the techniques used in manufacturing sectors to arrive for the best manufacturing conditions, which is an essential need for industries towards manufacturing of quality products at lower cost. This paper aims to investigate the optimal set of process parameters such as current, pulse ON and OFF time in Electrical Discharge Machining (EDM) process to identify the variations in three performance characteristics such as rate of material removal, wear rate on tool, and surf...

We perform a study on the predictions of electric-dipole moments (EDMs) of neutron, Mercury (Hg), Thallium (Tl), deuteron, and Radium (Ra) in the framework of next-to-minimal supersymmetric standard model (NMSSM) with CP-violating parameters in the superpotential and soft-supersymmetry-breaking sector. We confine to the case in which only the physical tree-level CP phase $(\\phi'_\\lambda - \\phi'_\\kappa)$, associated with the couplings of the singlet terms in the superpotentia...

A PNPI/ILL experiment to measure the neutron electric dipole moment (EDM) is currently being prepared at the facility PF2 for ultracold neutrons (UCN) at the Institut Laue-Langevin in Grenoble. To enable an improvement of sensitivity, one of PF2's beam positions has been equipped with new components for UCN transport, polarization and beam characterization, comprised of a superconducting solenoid-polarizer with magnetic field 4 T, a neutron guide system with diameter 136 mm prepared in replica technology, and a novel beam chopper for time-of-flight analysis. The whole EDM apparatus is set up on a non-magnetic platform. The total flux of polarized UCN with velocities less than 6.8 m/s along the guide axis is 1.5x105 n/s, corresponding to a flux density of 103 cm-2 s-1. The density of polarized UCN at the experimental position is about 5 cm-3, which shall lead to an EDM measurement with a counting statistical accuracy of 1.5x10-26 ecm during 200 days of operation at PF2.

The constraint on the $R$-parity violating supersymmetric interactions is discussed in the light of current experimental data of the electric dipole moment of neutron, $^{129}$Xe , $^{205}$Tl, and $^{199}$Hg atoms, and YbF and ThO molecules. To investigate the constraints without relying upon the assumption of the dominance of a particular combination of couplings over all the rest, an extensive use is made of the linear programming method in the scan of the parameter space. We give maximally possible values for the EDMs of the proton, deuteron, $^3$He nucleus, $^{211}$Rn, $^{225}$Ra, $^{210}$Fr, and the $R$-correlation of the neutron beta decay within the constraints from the current experimental data of the EDMs of neutron, $^{129}$Xe, $^{205}$Tl, and $^{199}$Hg atoms, and YbF and ThO molecules using the linear programming method. It is found that the $R$-correlation of the neutron beta decay and hadronic EDMs are very useful observables to constrain definite regions of the parameter space of the $R$-parity...

Electro Discharge Machine (EDM) is the commonest untraditional method of production for forming metals and the Non-Oxide ceramics. The increase of smoothness, the increase of the remove of filings, and also the decrease of proportional erosion tool has an important role in this machining. That is directly related to the choosing of input parameters.The complicated and non-linear nature of EDM has made the process impossible with usual and classic method. So far, some methods have been used based on intelligence to optimize this process. At the top of them we can mention artificial neural network that has modelled the process as a black box. The problem of this kind of machining is seen when a workpiece is composited of the collection of carbon-based materials such as silicon carbide. In this article, besides using the new method of mono-pulse technical of EDM, we design a fuzzy neural network and model it. Then the genetic algorithm is used to find the optimal inputs of machine. In our research, workpiece is a Non-Oxide metal called silicon carbide. That makes the control process more difficult. At last, the results are compared with the previous methods.

We analyze the correlations between electric dipole moments (EDMs) of the neutron and heavy atoms and CP violation in B_{s,d} mixing in two Higgs doublet models respecting the Minimal Flavour Violation hypothesis, with flavour-blind CP-violating (CPV) phases. In particular, we consider the case of flavour-blind CPV phases from i) the Yukawa interactions and ii) the Higgs potential. We show that in both cases the upper bounds on the above EDMs do not forbid sizable non-standard CPV effects in B_s mixing. However, if a large CPV phase in B_s mixing will be confirmed, this will imply EDMs very close to their present experimental bounds, within the reach of the next generation of experiments, as well as BR(B_{s,d}-> mu^+ mu^-) typically largely enhanced over its SM expectation. The two flavour-blind CPV mechanisms can be distinguished through the correlation between S_psi K_S and S_psi phi that is strikingly different if only one of them is relevant. Which of these two CPV mechanisms dominates depends on the prec...

DNA methylation is important for the silencing of transposons and other repetitive elements in many higher eukaryotes. However, plant and mammalian genomes have evolved to contain repetitive elements near or inside their genes. How these genes are kept from being silenced by DNA methylation is not well understood. A forward genetics screen led to the identification of the putative chromatin regulator Enhanced Downy Mildew 2 (EDM2) as a cellular antisilencing factor and regulator of genome DNA methylation patterns. EDM2 contains a composite Plant Homeo Domain that recognizes both active and repressive histone methylation marks at the intronic repeat elements in genes such as the Histone 3 lysine 9 demethylase gene Increase in BONSAI Methylation 1 (IBM1) and is necessary for maintaining the expression of these genes by promoting mRNA distal polyadenylation. Because of its role in maintaining IBM1 expression, EDM2 is required for preventing CHG methylation in the bodies of thousands of genes. Our results thus increase the understanding of antisilencing, genome methylation patterns, and regulation of alternative RNA processing by intronic heterochromatin. PMID:24248388

Mechanical test specimens can be easily manufactured from Zr-2.5Nb pressure tubes using electrical discharge machining (EDM). We discovered that zirconium specimens manufactured by EDM using a brass electrode and paraffin oil as dielectric fluid picked up a large amount of hydrogen during irradiation in 250°C water. This paper describes the investigation of the hydrogen ingress route. Our results showed that EDM in paraffin oil using a brass electrode modified the surface such that it became permeable for hydrogen when the specimen was later exposed to water. Out-reactor experiments on unirradiated material showed that irradiation was not necessary for the hydrogen ingress but might influence the ingress rate. The hydrogen ingress rate for out-reactor tests was estimated to be in the range 2 × 10 17-8 × 10 17 atoms/m 2 s at 300°C water. There was a large scatter in the results indicating that the surface conditions, water chemistry and radiolysis of the water may influence the hydrogen ingress rate.

Mechanical test specimens can be easily manufactured from Zr-2.5Nb pressure tubes using electrical discharge machining (EDM). We discovered that zirconium specimens manufactured by EDM using a brass electrode and paraffin oil as dielectric fluid picked up a large amount of hydrogen during irradiation in 250 C water. This paper describes the investigation of the hydrogen ingress route. Our results showed that EDM in paraffin oil using a brass electrode modified the surface such that it became permeable for hydrogen when the specimen was later exposed to water. Out-reactor experiments on unirradiated material showed that irradiation was not necessary for the hydrogen ingress but might influence the ingress rate. The hydrogen ingress rate for out-reactor tests was estimated to be in the range 2 x 1017-8 x 1017 atoms/m2 s at 300 C water. There was a large scatter in the results indicating that the surface conditions, water chemistry and radiolysis of the water may influence the hydrogen ingress rate. (orig.)

The EDM processing characteristics of one of the nickel-based heat resistant alloys, Hastelloy-X, were investigated under the various EDM conditions and analyzed in terms of surface integrity. This alloy is commonly used as a material for the hot gas path component of gas turbines and it is difficult to machine by conventional machining methods. The primary EDM parameter which was varied in this study were the pulse-on time. Since the pulse-on time is one of the main factors that determines the intensity of the electrical discharge energy, it was expected that the machining ratio and the surface integrity of the specimens would be proportionally dependent on the pulse-on duration. However, experimental results showed that MRR (Material Removal Rate) and EWR (Electrode Wear Rate) behaved nonlinearly with respect to the pulse duration, whereas the morphological and metallurgical features showed rather a constant trend of change by the pulse duration. In addition the heat treating process affected the recast layer and HAZ to be recrystallized but softening occurred in recast layer only. A metallurgical evaluation of the microstructure for the altered material zone was also conducted

The EDM processing characteristics of one of the nickel-based heat resistant alloys, Hastelloy-X, were investigated under the various EDM conditions and analyzed in terms of surface integrity. This alloy is commonly used as a material for the hot gas path component of gas turbines and it is difficult to machine by conventional machining methods. The primary EDM parameter which was varied in this study were the pulse-on time. Since the pulse-on time is one of the main factors that determines the intensity of the electrical discharge energy, it was expected that the machining ratio and the surface integrity of the specimens would be proportionally dependent on the pulse-on duration. However, experimental results showed that MRR (Material Removal Rate) and EWR (Electrode Wear Rate) behaved nonlinearly with respect to the pulse duration, whereas the morphological and metallurgical features showed rather a constant trend of change by the pulse duration. In addition the heat treating process affected the recast layer and HAZ to be recrystallized but softening occurred in recast layer only. A metallurgical evaluation of the microstructure for the altered material zone was also conducted.

DNA methylation is important for the silencing of transposons and other repetitive elements in many higher eukaryotes. However, plant and mammalian genomes have evolved to contain repetitive elements near or inside their genes. How these genes are kept from being silenced by DNA methylation is not well understood. A forward genetics screen led to the identification of the putative chromatin regulator Enhanced Downy Mildew 2 (EDM2) as a cellular antisilencing factor and regulator of genome DNA methylation patterns. EDM2 contains a composite Plant Homeo Domain that recognizes both active and repressive histone methylation marks at the intronic repeat elements in genes such as the Histone 3 lysine 9 demethylase gene Increase in BONSAI Methylation 1 (IBM1) and is necessary for maintaining the expression of these genes by promoting mRNA distal polyadenylation. Because of its role in maintaining IBM1 expression, EDM2 is required for preventing CHG methylation in the bodies of thousands of genes. Our results thus increase the understanding of antisilencing, genome methylation patterns, and regulation of alternative RNA processing by intronic heterochromatin. PMID:24248388

Full Text Available SciELO Brazil | Language: English Abstract in english At present, due to their properties, the tungsten carbide-cobalt (WC-Co) composite materials are in huge demand by industry to manufacture special tools, dies/molds and components under erosion. The powder metallurgy is the usual process applied to obtain WC-Co products, but in some cases this proce [...] ss is unable to produce tools of very complex shapes and highly intricate details. Thus, additional conventional and non-conventional machining processes are required. In this context, the electrical discharge machining (EDM) is an efficient alternative process. However, the EDM parameters have to be properly set for any different tungsten carbide-cobalt composition and electrode material to achieve an appropriate level of machining performance. In this work, a special grade of tungsten carbide-cobalt was used as workpiece and a copper-tungsten alloy as electrode. Experiments on important EDM electrical and non-electrical parameter settings with reference to material removal rate, electrode wear ratio and surface roughness were carried out under typical rough and finish machining. This paper contributes with an attempt to provide insightful guidelines to optimize electrical discharge machining of WC-Co composite materials using CuW alloy electrodes.

We present in this work results concerning the application of the generalized simulated annealing (GSA) algorithm to the LEED search problem. The influence of the visiting distribution function (defined by the so-called qV parameter) in the effectiveness of the method was investigated by the application of the algorithm to structural searches for optimization of two to ten parameters in a theory-theory comparison for the CdTe(110) system. Results, obtained with the scaling relation and probability of convergence as a function of the number of parameters to be varied, indicate the fast simulated annealing (FSA) (qV = 2.0) approach as the best search machine

Full Text Available This paper describes an experimental study to evaluate the effect of Span20 surfactant and Graphite powder (additives added to the dielectric fluid on the machining characteristics of the Titanium alloy using Electrical Discharge Machining (EDM. Variation of material removal rate, surface roughness and tool wear rate with respect to the variation in discharge current is evaluated. Comparison is made between the performance characteristics of the Titanium alloy with and without additives added to the dielectric fluid in the machining process. Increase in Material Removal Rate (MRR and decrease in Tool Wear Rate (TWR and Surface Roughness (SR were observed, when the material is machined with additives added in the dielectric fluid compared to the machining of the alloy without additives added in the dielectric fluid. The Scanning Electron Microscope (SEM photograph observed that the recast layer thickness is low and on the machined upper surface less micro cracks and craters are formed. Energy Dispersive Spectroscopy (EDS analysis also indicates that some amounts of material were transferred from electrode to workpiece.

The magnetic dipole interaction played a central role in the development of QED, and continued in that role for the Standard Model. The muon anomalous magnetic moment has served as a benchmark for models of new physics, and the present experimental value is larger than the standard-model value by more than three standard deviations. The electric dipole moment (EDM) violates parity (P) and time-reversal (T) symmetries, and in the context of the CPT theorem, the combination of charge conjugation and parity (CP). Since a new source of CP violation outside of that observed in the K and B meson systems is needed to help explain the baryon asymmetry of the universe, searches for EDMs are being carried out worldwide on a number of systems. The standard-model value of the EDM is immeasurably small, so any evidence for an EDM would signify the observation of new physics. Unique opportunities exist for EDMsearches using polarized proton, deuteron or muon beams in storage rings. This talk will provide an overview of the theory of dipole moments, and the relevant experiments. The connection to the transition dipole moment that could produce lepton flavor violating interactions such as ?+ ? e+? is also mentioned.

The MiniBooNE Collaboration reports first results of a search for ?e appearance in a ?? beam. With two largely independent analyses, we observe no significant excess of events above the background for reconstructed neutrino energies above 475 MeV. The data are consistent with no oscillations within a two-neutrino appearance-only oscillation model

An improved experiment searching for the neutron electric dipole moment is currently being set up at the new high-intensity ultracold neutron (UCN) source at the Paul Scherrer Institut, Switzerland. In order to control ambient magnetic field fluctuations, an external field compensation coil system together with a 4-layer high permeability magnetic shield is used. Residual magnetic field fluctuations inside the ultracold neutron storage chamber are measured by a mercury co-magnetometer. With the expected increase in sensitivity due to the increased UCN densities, it has become essential to also improve the mercury co-magnetometer. The working principle, planned improvements and first results for the mercury co-magnetometer are presented.

We explored several viable scenarios of how LAT might observe DM, when the spectral feature is predicted to be observed in the HE electron flux It has been demonstrated elsewhere that LAT will be capable to detect HE electrons flux in energy range from 20 GeV to - 1 TeV with 520% energy resolution and good statistics If there is a DM-caused feature in the HE electron flux (in the range 20 GeV - 1 TeV), LAT will be the best current instrument to observe it!

Understanding the ability to measure and discriminate particle events at the lowest possible energy is an essential requirement in developing new experiments to search for weakly interacting massive particle (WIMP) dark matter. In this paper we detail an assessment of the potential sensitivity below 10 keV in the 1 m3 DRIFT-II directionally sensitive, low pressure, negative ion time projection chamber (NITPC), based on event-by-event track reconstruction and calorimetry in the multiwire proportional chamber (MWPC) readout. By application of a digital smoothing polynomial it is shown that the detector is sensitive to sulfur and carbon recoils down to 2.9 and 1.9 keV respectively, and 1.2 keV for electron induced events. The energy sensitivity is demonstrated through the 5.9 keV gamma spectrum of 55Fe, where the energy resolution is sufficient to identify the escape peak. The effect of a lower energy sensitivity on the WIMP exclusion limit is demonstrated. In addition to recoil direction reconstruction for WIMP searches this sensitivity suggests new prospects for applications also in KK axion searches.

We describe an experiment to search for a new vector boson A' with weak coupling alpha' > 6 x 10^{-8} alpha to electrons (alpha=e^2/4pi) in the mass range 65 MeV < m_A' < 550 MeV. New vector bosons with such small couplings arise naturally from a small kinetic mixing of the "dark photon" A' with the photon -- one of the very few ways in which new forces can couple to the Standard Model -- and have received considerable attention as an explanation of various dark matter related anomalies. A' bosons are produced by radiation off an electron beam, and could appear as narrow resonances with small production cross-section in the trident e+e- spectrum. We summarize the experimental approach described in a proposal submitted to Jefferson Laboratory's PAC35, PR-10-009. This experiment, the A' Experiment (APEX), uses the electron beam of the Continuous Electron Beam Accelerator Facility at Jefferson Laboratory (CEBAF) at energies of ~1-4 GeV incident on 0.5-10% radiation length Tungsten wire mesh targets, and me...

The A' EXperiment (APEX) is designed to search for new vector bosons that have small couplings to charged particles. Such vectors can arise naturally from a small kinetic mixing of a new 'dark photon' (A') with the photon - one of the very few ways in which new forces can couple to the Standard Model - and have received considerable attention as an explanation of various dark matter related anomalies. A' bosons are produced by radiation off an electron beam, and could appear as narrow resonances with small production cross-section in the QED e+e? spectrum. We plan to search for an A' using the CEBAF electron beam at energies of 1-4 GeV incident on 0.5-10% radiation length multi-foil tungsten targets, and measure the resulting e+e? pairs using the High Resolution Spectrometers and a septum magnet in Hall A at Jefferson Lab. With a 33-day run, APEX will explore the region 50 MeV A? ?7. This proceeding summarizes the experiment, test run results, and comments on future plans

Electron scattering fixed target experiments are a versatile tool to probe various kinds of physics phenomena. Recently fixed target experiments in which an electron beam is scattered off a heavy nucleus and a lepton-antilepton pair is created, i.e. e(A,Z) ?e(A,Z)l+l?, were utilized to search for physics beyond the standard model at modest energies. In these experiments one searches for a small, narrow resonance in the invariant mass spectrum of the lepton-antilepton pair, arising from the exchange of a new light gauge boson ?? coupling to the dark sector as well as very weakly to standard model particles. Such a signal would appear as an enhancement over a smooth QED background. Hence a precise understanding of the background is crucial. We present a theoretical analysis of the process e(A,Z) ?e(A,Z)l+l?. Therefore we have performed an analysis of the cross section, which is then used to extract exclusion limits on the parameter space of the ??, describing the existing experimental data taken at MAMI

This proposal is part of an extended program dedicated to the neutrino-mass determination in the electron-capture sector, which aims at ultra-precise mass measurements by Penning traps in combination with cryogenic micro-calorimetry for atomic de-excitation measurements. Here, precise mass measurements with ISOLTRAP are proposed for the orbital electron-capture nuclides $^{194}$Hg and $^{2o2}$Pb, as well as their daughters, with the goal to determine accurately their Q-values. These values are expected to be the smallest ones among a great variety of known electron-capture precursors. Therefore, these nuclides are strong candidates for an improved electron-neutrino mass determination. We ask for 8 shifts of on-line beam at ISOLDE for mass measurements of $^{194}$Hg, $^{194}$ Au, $^{2o2}$Pb, and $^{2o2}$Tl at ISOLTRAP.

The author presents a search for excited or exotic electrons decaying to an electron and a photon with high transverse momentum. An oppositely charged electron is produced in association with the excited electron, yielding a final state dielectron + photon signature. The discovery of excited electrons would be a first indication of lepton compositeness. They use {approx} 202 pb{sup -1} of data collected in p{bar p} collisions at {radical}s = 1.96 TeV with the Collider Detector at Fermilab during March 2001 through September 2003. The data are consistent with standard model expectations. Upper limits are set on the experimental cross-section {sigma}({bar p}p {yields} ee* {yields} ee{gamma}) at the 95% confidence level in a contact-interaction model and a gauge-mediated interaction model. Limits are also presented as exclusion regions in the parameter space of the excited electron mass (M{sub e*}) and the compositeness energy scale ({Lambda}). In the contact-interaction model, for which there are no previously published limits, they find M{sub e*} < 906 GeV is excluded for M{sub e*} = {Lambda}. In the gauge-mediated model, the exclusion region in the M{sub e*} versus the phenomenological coupling f/{Lambda} parameter space is extended to M{sub e*} < 430 GeV for f/{Lambda} {approx} 10{sup -2} GeV{sup -1}. In comparison, other experiments have excluded M{sub e*} < 280 GeV for f/{Lambda} {approx} 10{sup -2} GeV{sup -1}.

Exotic dark matter and dark energy together seem to dominate in the Universe. Supersymmetry naturally provides a candidate for the dark matter constituents via the lightest supersymmetric particle (LSP). The most important process for directly detecting dark matter is the LSP-nucleus elastic scattering by measuring the energy of the recoiling nucleus. In the present work we explore a novel process, which has definite experimental advantages, that is the detection of the dark matter constituents by observing the low energy ionization electrons. These electrons, which are produced during the LSP-nucleus collision, may be observed separately or in coincidence with the recoiling nuclei. We develop the formalism and apply it in calculating the ratio of the ionization rate to the nuclear recoil rate in a variety of atoms including 20Ne, 40Ar, 76Ge, 78Kr and 132Xe, employing realistic Hartree-Fock electron wave functions. The obtained ratios are essentially independent of all parameters of supersymmetry except the neutralino mass, but they crucially depend on the electron energy cutoff. These ratios per electron tend to increase with the atomic number and can be as high as 10%. Based on our results it is both interesting and realistic to detect the LSP by measuring the ionization electrons following the LSP nuclear collisions

We report the result of a search for the pair production of the lightest supersymmetric partner of the top quark ($\\tilde{t}_1$) in $p\\bar{p}$ collisions at a center-of-mass energy of 1.96 TeV at the Fermilab Tevatron collider corresponding to an integrated luminosity of 5.4 fb$^{-1}$. The scalar top quarks are assumed to decay into a $b$ quark, a charged lepton, and a scalar neutrino ($\\tilde{\

Full Text Available É sabido que a Usinagem por Descargas Elétricas (EDM, é um processo térmico onde pode-se ter temperaturas muito elevadas (superiores a 1200 °C na região de usinagem. Conseqüentemente é fácil de entender o fato das peças usinadas por EDM, apresentarem camadas superficiais endurecidas, refundidas e com elevado números de microtrincas superfíciais. A formação de microtrincas está associada com o desenvolvimento de altas tensões térmicas que excedem a tensão máxima de resistência do material. Além disso as microtrincas superficiais penetram em profundidade com extensões que dependem da energia de descarga. O trabalho proposto, tem por objetivo estudar o efeito da adição de pó de SiC em vários fluidos dielétricos, sobre a geração de microtrincas superficiais, no aço rápido ABNT M2, durante a usinagem por descargas elétricas. Os resultados apresentados mostram uma redução da quantidade de microtrincas nas superfícies usinadas, quando se adiciona pó de SiC ao dielétrico, quando comparadas com as usinadas com EDM convencional.It is known that Electrical Discharge Machining (EDM, it is a thermal process where it can be had very high temperatures (higter than 1200° C in the region of machining consequently is easy to understand that during each electric discharge, hight temperatures are generated, causing local fusion or even evaporation of the material machined. In each discharge, a crater is formed in the material and a small crater is formed in the electrode. Of every melted material produced in each discharge, only 15%, or minus, it is removed through the dielectric liquid. The remaining of the melted material solidifies forming a wrinkled surface. The characteristics of the surface obtained, overlap of craters, globules of sullage, “chimneys ", bubbles (formed when the gases arrested are liberated through the material resolidificado, they are revealed through an analysis by scanning electron microscope. O proposed work, has for objective to study the effect of the addition of powder of SiC in several dielectric fluids, on microcrack generation, in workpiece of the high speed steel (ABNT M2, during the electrical discharge machining. The presented results show that the samples machined with the addition of powders of SiC presented significant reduction of the number of microcrack in the surface machined, when compared with the machined with conventional EDM.

The electric and magnetic dipole moments of dyon fermions are calculated within N=2 supersymmetric Yang-Mills theory including the ?-term. It is found, in particular, that the gyroelectric ratio deviates from the canonical value of 2 for the monopole fermion (nm=1, ne=0) in the case ??0. Then, applying the S-duality transformation to the result for the dyon fermions, we obtain an explicit prediction for the electric dipole moment (EDM) of the charged fermion ('electron'). It is thus seen that the approach presented here provides a novel method for computing the EDM induced by the ?-term. (author)

We describe an experiment to search for a new vector boson A' with weak coupling {alpha}' {approx}> 6 x 10{sup -8} {alpha} to electrons ({alpha} = e{sup 2}/4{pi}) in the mass range 65 MeV < m{sub A'} < 550 MeV. New vector bosons with such small couplings arise naturally from a small kinetic mixing of the 'dark photon' A' with the photon - one of the very few ways in which new forces can couple to the Standard Model - and have received considerable attention as an explanation of various dark matter related anomalies. A' bosons are produced by radiation off an electron beam, and could appear as narrow resonances with small production cross-section in the trident e{sup +}e{sup -} spectrum. We summarize the experimental approach described in a proposal submitted to Jefferson Laboratory's PAC35, PR-10-009. This experiment, the A' Experiment (APEX), uses the electron beam of the Continuous Electron Beam Accelerator Facility at Jefferson Laboratory (CEBAF) at energies of {approx} 1-4 GeV incident on 0.5-10% radiation length Tungsten wire mesh targets, and measures the resulting e{sup +}e{sup -} pairs to search for the A' using the High Resolution Spectrometer and the septum magnet in Hall A. With a {approx} 1 month run, APEX will achieve very good sensitivity because the statistics of e{sup +}e{sup -} pairs will be {approx} 10,000 times larger in the explored mass range than any previous search for the A' boson. These statistics and the excellent mass resolution of the spectrometers allow sensitivity to {alpha}'/{alpha} one to three orders of magnitude below current limits, in a region of parameter space of great theoretical and phenomenological interest. Similar experiments could also be performed at other facilities, such as the Mainz Microtron.

The Standard Model of particle physics has known a tremendous rise during the twentieth century. Built up, from the early thirties to the seventies, this theory describing elementary particles and their interactions (electromagnetic, weak, strong) has now been intensively tested by LEP and Tevatron colliders. Besides its success, some problems remain and have lead to new theories attempting to go beyond the standard model. Many of them are predicting the existence of a new gauge boson Z', which is supposed to be observed at the TeV scale. Data recorded by the LHC since autumn 2008 are a new opportunity to check the consistency of the Standard Model and to search for new physics evidence. The work that has been done by the ATLAS collaboration during the last four years has focused on understanding detector's behaviour and analysing the very first collected collisions. This thesis is reflecting these two aspects. Therefore, the first part of this thesis describes the characterisation of a pathology of ATLAS liquid argon calorimeter electronics and of coherent noise bursts that have both been observed since the beginning of ATLAS operation. The policy deployed to preserve data quality is also detailed. The second part is focusing on the search for new Z' gauge boson. In case this particle was to exist, its decay into an electron and a positron would lead to a new massive resonance in the dielectron invariant mass spectrum. Therefore electron reconstruction and identification performances are closely looked at, especially at high transverse momentum. Analysis made on the 4.9 fb-1 of collected data is reported. As no significant excess with respect to Standard Model predictions is observed, the dielectron invariant mass spectrum is interpreted to derive mass limits concerning the existence of new Z' gauge bosons appearing in grand unification theories (E6) and effective sequential standard model (SSM). These limits and those derived by the CMS collaboration are the best ever set on such new bosons. (author)

In this study we investigated indirect manifestations of color octet electron at the next generation linear colliders: International Linear Collider (ILC) and Compact Linear Collider (CLIC). Namely, production of two gluons via color octet electron exchange is considered. Signal and background analysis have been performed taking into account initial state radiation and beamstrahlung. We show that color octet electron (e_(8)) manifestation will be seen upto M(e_(8))=1.75 TeV and 1.70 TeV at ILC and CLIC with sqrt(s)=0.5 TeV, respectively. CLIC with sqrt(s)=3 TeV will be sensitive upto M(e_(8)=6.88 TeV.

Accessible to readers at all levels of technological understanding, this book covers all aspects of electronic data and how to manage it. It explains what electronic information is; where it is located; different ways it can be stored; why we need to manage it from a legal and organizational perspective; who is likely to control it; and how it should be acquired to meet legal and managerial goals. The text includes links and references to additional information, technical software solutions, as well as helpful forms and time-saving guides.

The Moessbauer effect on samples in the form of interchanging thin layers from magnetic metals (Co, Ni, Gd, Dy, Cr) and tin is studied. The investigation was aimed at determination of spin polarization of conduction electrons of the above metals by measuring superfine magnetic fields on the 119Sn nuclei. The measurement results of the Moessbauer spectra and the phase analysis of the samples using electron diffraction have shown that in the contacting regions of magnetic and nonmagnetic metals there appear alloys and compounds which hinders polarization penetration into the nonmagnetic metal. The penetration depth of polarization lambdasub(s)>=10-15 A is estimated

The MiniBooNE Collaboration reports initial results from a search for ?[over-bar] mu-->?[over-bar] e oscillations. A signal-blind analysis was performed using a data sample corresponding to 3.39×10[superscript 20] protons on target. The data are consistent with background prediction across the full range of neutrino energy reconstructed assuming quasielastic scattering, 200

11sec animation of a Higgs->ZZ->4e candidate in CMS. Real CMS proton-proton collision events in which 4 high energy electrons (orange lines and towers) are observed. The event shows characteristics expected from the decay of a Higgs boson but is also consistent with background Standard Model physics processes.

A significant energy dependence was observed in the region of the first diffraction minimum of the form factor for elastic electron scattering from /sup 12/C between 238 and 419 (and 431) MeV. This effect might be attributed to dispersive (two-step) processes

The next generation of particle edmsearches will be at such a high sensitivity that it will be possible for the results to be contaminated by a systematic error resulting from the interaction of the motional (E x v/c) magnetic field with stray field gradients. In this paper we extend previous work to present an analytic form for the frequency shift in the case of a rectangular storage vessel and discuss the implications of the result for the neutron edm experiment which will be installed at the SNS (Spallation Neutron Source) by the LANL collaboration

Wire EDM is in use for a long time for cutting punches and dies, shaped pockets and other machine parts. Surface finish of the machined surface mainly depends on current and voltage used during machining. In the present research experimental investigations have been conducted to establish relationships of job surface finish with current and voltage. Brass wires of diameters 0.3, 0.25, 0.20 and 0.15 mm were used. Work materials tested were mild steel, aluminum, cemented carbide, copper and sta...

This paper describes a new machining process which combines twin-electro-wire together with two electro discharge circuits to rapidly fabricate micro electrode tools. The results show that transistor electro discharge and RC electro discharge circuits coexist to fabricate micro tools with rough and finish machining both on the same machine. Compared to conventional wire electro discharge grinding (WEDG) technology, a twin-wire EDM system that combines rough and finish machining into one process allows the efficient fabrication of micro tools. This high-speed micro tool fabrication process can be applied not only to micro electrode machining but also to micro punching tool and micro probing tips machining.

Full Text Available For the measurement of the electron electric dipole moment using Fr atoms, a Fr ion-atom conversion is one of the most critical process. An ion-atom converter based on the “orthotropic” type of Fr source has been developed. This converter is able to convert a few keV Fr ion beam to a thermal atomic beam using a cycle of the surface ionization and neutralization. In this article, the development of the converter is reported.

For the measurement of the electron electric dipole moment using Fr atoms, a Fr ion-atom conversion is one of the most critical process. An ion-atom converter based on the “orthotropic” type of Fr source has been developed. This converter is able to convert a few keV Fr ion beam to a thermal atomic beam using a cycle of the surface ionization and neutralization. In this article, the development of the converter is reported.

A search for {ital t{bar t}}{r arrow}{ital e}{mu}+{ital X} in {ital p{bar p}} collisions at {ital s}{bar {radical}} TeV is described. The production and decay of top-quark--antiquark pairs is considered in the context of the standard model. The analysis is based on data with an integrated luminosity of 4.4 pb{sup {minus}1} recorded with the Collider Detector at Fermilab. An upper limit on the {ital t{bar t}} cross section is obtained, and the top quark in the mass range 28--72 GeV/{ital c}{sup 2} is excluded at the 95% C.L. The same limits apply to a possible fourth-generation, charge {minus}1/3, {ital b}{prime} quark, decaying via the charged current.

A search for t bar t?e?+X in p bar p collisions at s bar ? TeV is described. The production and decay of top-quark--antiquark pairs is considered in the context of the standard model. The analysis is based on data with an integrated luminosity of 4.4 pb-1 recorded with the Collider Detector at Fermilab. An upper limit on the t bar t cross section is obtained, and the top quark in the mass range 28--72 GeV/c2 is excluded at the 95% C.L. The same limits apply to a possible fourth-generation, charge -1/3, b' quark, decaying via the charged current

We have searched for the pair production of first generation scalar leptoquarks in the eejj channel using the full data set (123 pb-1) collected with the D0 detector at the Fermilab Tevatron during 1992 endash 1996. We observe no candidates with an expected background of approximately 0.4 events. Comparing the experimental 95% confidence level upper limit to theoretical calculations of the cross section with the assumption of a 100% branching fraction of eq, we set a lower limit on the mass of a first generation scalar leptoquark of 225 GeV/c2. The results of this analysis rule out the interpretation of the excess of high Q2 events at DESY HERA as leptoquarks which decay exclusively to eq. copyright 1997 The American Physical Society

The start of the Large Hadron Collider (LHC) opened a new window to the energy scale far beyond 1 TeV. There are different theories that predict new physics, and hence it is not clear what signature to expect in the data and which of the theory will describe it properly. However new physics could as well manifest itself in ways no one has yet thought of. Thus we have implemented a Model Unspecific Search in CMS (MUSiC). This approach has been applied to the CMS data and we have obtained the preliminary results. I will talk about this details of the analysis techniques, its implementation in analysing CMS data, results obtained and the discussion on the discrepancy observed

A joint effort of cryogenic microcalorimetry (CM) and high-precision Penning-trap mass spectrometry (PT-MS) in investigating atomic orbital electron capture (EC) can shed light on the possible existence of heavy sterile neutrinos with masses from 0.5 to 100 keV. Sterile neutrinos are expected to perturb the shape of the atomic de-excitation spectrum measured by CM after a capture of the atomic orbital electrons by a nucleus. This effect should be observable in the ratios of the capture probabilities from different orbits. The sensitivity of the ratio values to the contribution of sterile neutrinos strongly depends on how accurately the mass difference between the parent and the daughter nuclides of EC transitions can be measured by, for example, PT-MS. A comparison of such probability ratios in different isotopes of a certain chemical element allows one to exclude many systematic uncertainties, and thus could make feasible a determination of the contribution of sterile neutrinos on a level below 1%. Several electron capture transitions suitable for such measurements are discussed.

A joint effort of cryogenic microcalorimetry (CM) and high-precision Penning-trap mass spectrometry (PT-MS) in investigating atomic orbital electron capture (EC) can shed light on the possible existence of heavy sterile neutrinos with masses from 0.5 to 100 keV. Sterile neutrinos are expected to perturb the shape of the atomic de-excitation spectrum measured by CM after a capture of the atomic orbital electrons by a nucleus. This effect should be observable in the ratios of the capture probabilities from different orbits. The sensitivity of the ratio values to the contribution of sterile neutrinos strongly depends on how accurately the mass difference between the parent and the daughter nuclides of EC-transitions can be measured by, e.g., PT-MS. A comparison of such probability ratios in different isotopes of a certain chemical element allows one to exclude many systematic uncertainties and thus could make feasible a determination of the contribution of sterile neutrinos on a level below 1%. Several electron ...

There has been exciting progress in recent years in the search for a spin-aligned electric dipole moment (EDM) of atoms, molecules, and the neutron. Although such a time-reversal violating dipole has not yet been detected, highly touted theories of possible new physics, such as Supersymmetry, predict the existence of EDMs within reach of modern experiments. In 2001 our group published a precise limit on the EDM of the ^199Hg atom: |d(Hg)|magnetic and anti-parallel electric fields, resulting in EDM-sensitive spin precession; the other two cells, at zero electric field, serve to cancel magnetic gradient noise and limit systematics due to magnetic impurities or leakage currents. To date, the statistical uncertainty for the new EDM data is1.7 x 10-29 e cm. Constraining systematics to similar levels will thus yield an order of magnitude improvement over our previous measurement. The talk will highlight recent work and show our current results. This research is supported by NSF Grant PHY 0457320.

Understanding the ability to measure and discriminate particle events at the lowest possible energy is an essential requirement in developing new experiments to search for weakly interacting massive particle (WIMP) dark matter. In this paper we detail an assessment of the potential sensitivity below 10 keV in the 1 m^3 DRIFT-II directionally sensitive, low pressure, negative ion time projection chamber (NITPC), based on event-by-event track reconstruction and calorimetry in the multiwire proportional chamber (MWPC) readout. By application of a digital smoothing polynomial it is shown that the detector is sensitive to sulfur and carbon recoils down to 3.5 and 2.2 keV respectively, and 1.2 keV for electron induced tracks. The energy sensitivity is demonstrated through the 5.9 keV gamma spectrum of 55Fe, where the energy resolution is sufficient to identify the escape peak. In addition to recoil direction reconstruction for WIMP searches this sensitivity suggests new prospects for applications also in KK axion s...

Neutrino-electron elastic scattering reactions play an important role in tests of weak interaction theory. The four reactions which may be considered are:. (nu)(,e) + e('-) (--->) (nu)(,e) + e('-). (nu)(,e)(' )+ e('-) (--->) (nu)(,e) + e('-). (nu)(,(mu)) + e('-) (--->) (nu)(,(mu)) + e('-). (nu)(,(mu))(' )+ e('-) (--->) (nu)(,(mu)) + e(' -). The experimental study of these purely leptonic interactions severely tests basic theoretical ideas, and the reaction with (nu)(,e) has not yet been observed. The characteristics of Los Alamos Meson Physics Facility. (LAMPF) are such that (nu)(,e) is rarely produced, whereas (nu)(,e),(nu)(,(mu)), and(' ). (nu)(,(mu)) are present in equal numbers. Thus, data on all three processes(' ). will be collected simultaneously, but the (nu)(,e) reaction is expected to dominate. However, such studies are exceedingly difficult. The main problem arises from the nature of the event signature (an undetected particle enters the detector producing a single recoil electron) coupled with the miniscule cross sections expected (and therefore low event rates) amid numerous sources of background events. To learn how to reduce the rates of such backgrounds, the UCI Neutrino Group installed in the Neutrino Facility in 1974 a small scale detector system consisting of a sandwich of optical spark chambers and plastic scintillator slabs (0.38 metric tons) which was shielded by 2 1/2" of Pb and enclosed by tanks of liquid scintillator used as an anticoincidence. Electronics and instrumentation, including a CAMAC system interfaced with a PDP-11/05 computer, were housed in a nearby trailer. The 1974 study was carried out with the LAMPF Neutrino Facility shielded against cosmic rays by Fe walls 3' thick and a 4' Fe roof. Nevertheless, stopping cosmic ray muons appeared to give rise to the substantial number of background electron events observed. Several techniques were invoked to reduce the potential background for neutrino -electron elastic scattering to (1.5 (+OR-) 0.5) day('-1). Improved statistics from 1976 gave (1.48 (+OR-) 0.34) day('-1). If this number could be further reduced--by additional shielding, for example--then the experiment would be easier. However, data taken in 1975 with varying thicknesses of Pb on top of the sandwich detector and in 1976 with an additional 1' of Fe on the roof showed that there is no significant advantage to having more Pb or Fe in those areas. The accelerator may also be a source of background. When the accelerator is operating, neutrons from the beam stop can penetrate the Fe shielding to produce an excessive trigger rate (energetic neutrons) or on excessive dead time (thermal neutrons), especially in the more massive ANTI required for the full scale experiment. However, data taken in 1974 with 10(mu)A accelerator current and 4m Fe as beam stop shielding, and in 1976 with 100 (mu)A and 5m Fe, showed that the neutron flux was well under control. The ultimate configuration requires much higher beam currents, but also calls for additional Fe so that neutrons will not be a problem. In both 1974 and 1976 there were no electron events remaining in the accelerator data following subtraction of cosmic ray background. This fact can be used to set an upper limit on the elastic scattering cross section for (nu)(,e):. (sigma)(,exp) flash chamber modules and plastic scintillator slabs. Developmental work for the full scale detector system began in 1977, and some of the subsequent construction work is still in progress. However, the Neutrino Facility has been prepared, and portions of the sandwich detector have been installed. The first information on neutrino -electron elastic scattering could be available by the middle of 1982.

We analyze the effects of CP-violating phases on the electric dipole moment (EDM) of electron and neutron in the constrained minimal supersymmetric model. We find that the phases phi_{\\mu} and phi_{A_0} have to be strongly correlated, in particular for small values of the SUSY mass parameters. We calculate the neutron EDM in two different models, the Quark-Parton Model and the Chiral Quark Model. It turns out that the predictions are quite sensitive to the model used. We show parameter regions in the M_0-M_1/2 plane which are excluded by considering simultaneously the experimental bounds of both electron and neutron EDM, assuming specific values for the phases phi_{\\mu} and phi_{A_0}.

Full Text Available SciELO Brazil | Language: English Abstract in english The electrical discharge machining (EDM) is a process characterized by high thermal demands, which tend to cause metallurgical changes in the surface of the workpiece [1-2]. This work aims to conduct a discussion of metallurgical changes in the surface of cavities obtained by the process of EDM in t [...] he machining of steel. Several variables were employed, such as cavity depth, electrode geometry and technological parameters of the process. Thus, the goal was to identify the different metallurgical changes that can occur in the machined surfaces. The evaluation of these changes was made from metallographic analysis, measurements of microhardness and of the depth of the layer affected by process. The results of this work identified several metallurgical changes such as formation of white layer, hardness variation and change of microstructure. The occurrence of microcracks also was observed, especially in severe conditions. The greatest variations in results were caused by the change of technological parameters. However, the variation in cavity depth and the change of the electrode geometry also showed influence on the results.

We have been investigating the frequency stability of the low-frequency nuclear spin maser with ^129Xe aiming at EDM (permanent Electric Dipole Moment) experiment. One of the main sources for this frequency instability comes from the field fluctuation of the applied static magnetic field in a relatively long time scale. The present stability 30 nG of the applied field B0=30 mG in a time scale of 10^4 s should be suppressed in order to perform EDM experiment. We have been preparing for introduction of magnetometer to stabilize the magnet current to produce the B0 field. This magnetometer utilizes NMOE (Nonlinear Magneto Optical Effect) in Rb atom. The expected sensitivity of this type of magnetometer achieves the order of pG. We will report on systematic measurement of NMOE in Rb atom with different type of Rb cells using a tunable external-cavity diode laser, and on present status for the development of this type of magnetometer.

This paper describes a new method of die surface modification by ordinary Electrical Discharge Machining (EDM) tool. First, the principle of this method is studied. Secondly, the reason for appearance of cracks on the surface of coating layer in the electrical discharge coating with conventional pulse power supply are analyzed. At last, the new type special pulse power supply with additional pulse current is designed. Scenix single-chip is selected as pulse generator, which runs the fastest among all single-chips. The corresponding program can make the pulse power supply produce the additional pulse current. At the same time, the special pulse power supply can communicate different machining parameters with industrial personal computer by serial port of PIC single-chip according to the coating requires, and then PIC single-chip convey machining parameters to Scenix single-chip by the communication interface. Through process experiment, the special pulse power supply for electrical discharge coating behaves well, and the compacted coating layer without cracks deposited on the surface of die by EDM can be obtained, which can prolong the life of die.

A large number of micro holes are needed for biomedical parts, ink-jet nozzles and micro droplet spraying parts. In this study, an inexpensive machining approach for producing a batch of micro holes is proposed. A set of previously introduced w-EDM mechanisms is employed to horizontally cut the batch micro electrodes precisely. Through the process arrangement, the micro electrodes and workpiece are not unloaded, repositioned and re-corrected until all the tasks are completed. The micro workpiece is clamped onto the specially designed jig and moved above the micro electrodes to perform machining of the mass micro holes by upward batch micro EDM. The entire procedure is carried out on a developed multifunctional tabletop CNC machine tool. An array of 400 through holes of the identical sizes is successfully fabricated on a stainless-steel plate with a thickness of 30 µm by using the modified peck-drilling method. Experimental results confirmed that the proposed approach could accelerate the removal of debris, reduce the occurrence of abnormal discharges and decrease the machining time.

Full Text Available The correct selection of manufacturing conditions is one of the most important aspects to take into consideration in the majority of manufacturing processes and, particularly, in processes related to Electrical Discharge Machining (EDM. It is a capable of machining geometrically complex or hard material components, that are precise and difficult-to-machine such as heat treated tool steels, composites, super alloys, ceramics, carbides, heat resistant steels etc. being widely used in die and mold making industries, aerospace, aeronautics and nuclear industries. OHNS-EN-31 is a high car bon alloy steel which achieves high degree of hardness with compressive strength and abrasive resistance. OHNS-EN-31 steel, which is popularly used in automotive type applications, like axle, bearings, spindle and molding dies etc. In this paper we have tried to investigate effect of machining parameter such as discharge current, pulse on time, and pulse of time on MRR in EDM while machining OHNS-EN-31 STEEL using Cu tool . A well-designed experimental scheme was used to reduce the total number of experiments. Parts of the experiment were conducted with the L18 orthogonal array based on the Taguchi method. The results of analysis of variance (ANOVA indicate that the proposed mathematical model can be adequately describe the performance within the limit of factors being studied. The optimal set of process parameters has also been predicted to maximize the MRR.

Full Text Available Electric discharge machining (EDM has achieved remarkable success in the manufacture of conductive ceramic materials for the modern metal industry. The mathematical models are proposed for the modeling and analysis of the effects of machining parameters on the performance characteristics in the EDM process of WC/5Ni, Which is produced through powder metallurgy route. Response surface methodology (RSMis used to explain the influences of four machining parameters ; tool rotational speed(S, discharge current(C, pulse-on time(T and flushing pressure(P on the performance characteristics of the material removal rate (MRR, and surface roughness (Ra. The experiment plan adopts the central composite design (CCD. The separable influence of individual machining parameters and the interaction between these parameters are also investigated by using analysis of variance (ANOVA. This study highlights that the proposed mathematical models have proven to fit and predict values of performance characteristics close to those readings recorded experimentally with a 95% confidence interval. Results shows that are the two significant factors affecting material removal rate (MRR are discharge current and flushing pressure. The discharge current, flushing pressure and electrode rotation have statistical significance on the surface roughness (Ra.

Following the discovery of correlated positron -electron peaks in heavy ion experiments, the existence of a previously undetected particle coupling to e ^+e^- was postulated. A new experiment with improved sensitivity was suggested to detect this particle. Monoenergetic positrons would be accelerated onto electrons in a lithium target and the kinematics of the e^+e ^- scattering events measured by energy and position sensitive detectors. The experiment was carried out at Brookhaven National Laboratory where a 3 MV Dynamitron electrostatic accelerator was converted to a positron accelerator. The monoenergetic positrons were provided by a ^{22} Na source in conjunction with a thin single crystal tungsten moderator, and accelerated by the Dynamitron to a tunable energy between 1.0 and 2.5 MeV with keV resolution. The beam was transported through a new beam line to the target chamber where it could be focused down to 1 mm spot size. The energy of the interactions of the positrons with the lithium target was measured by plastic scintillators, and the position of the scattered particles was recorded by a set of four multi-wire proportional chambers capable of sub millimeter resolution. In a first experiment, the positron beam was scanned between 2150 and 2350 keV in 5 keV steps onto a 1.5 mg/cm ^2 lithium target with at least 60 000 coincidences recorded per energy point. The full kinematics of each positron-electron scattering event was reconstructed. The positron-nucleus scattering events were also detected and served as a normalization to eliminate all beam and target effects. A normalized e^+-e ^- scattering excitation function was derived, leading to an upper limit (90% CL) to the cross section for pointlike particles of sigma~ 1-5 mb. This translates to lower limits on the lifetime of tau>= 0.5 to 7 times10^{13} sec. In an extended run, data were acquired on a 2.5 mg/cm^2 lithium target from 1350 keV to 2350 keV in 3.5 keV steps with ~ 300 000 coincidences per point. These data were analyzed by X. Wu in an analogous way to the first run. These data yield lower limits on the lifetime of 3.3 times10^{-13} sec and 8.2 times10^{-13} sec for J = 0 and J = 1 resonances, respectively, over the invariant mass range 1560 keV/c^2 < M _{{rm X^0}} < 1860 keV/c^2. (Abstract shortened by UMI.).

Electron antineutrino interactions above the inverse beta decay energy of protons (E anti ?e>1.8 MeV) were looked for with the Borexino counting test facility (CTF). One candidate event survived after rejection of background, which included muon-induced neutrons and random coincidences. An upper limit on the solar anti ? flux, assumed having the 8B solar neutrino energy spectrum, of 1.1 x 105 cm-2s-1 (90% C.L.) was set with a 7.8 ton x year exposure. This upper limit corresponds to a solar neutrino transition probability, ?e? anti ?e, of 0.02 (90% C.L.). Predictions for antineutrino detection with Borexino, including geoneutrinos, are discussed on the basis of background measurements performed with the CTF. (orig.)

RINGS is a relational database built from NIST Crystal Data for the identification of polycrystalline solids by selected area electron diffraction (SAED) and elemental analysis using Microsoft® Access 97(subsequently converted to Access 2000). Experimental d-spacings are matched against values calculated from reduced unit cells, thereby fully and rigorously incorporating the effects of double diffraction. A total of 79,136 inorganic phases are included with original Crystal Data reference codes, allowing access to all information in NIST Crystal Data. Specific examples illustrate the advantages over previous approaches to the problem. This database will be most useful to researchers in mineralogy, metallurgy, materials science, forensics, and analytical chemisty who seek to identify well-characterized phases with known unit cells.

MiniBooNE seeks to corroborate or refute the unconfirmed oscillation result from the LSND experiment. If correct, the result implies that a new kind of massive neutrino, with no weak interactions, participates in neutrino oscillations. MiniBooNE searches for {nu}{sub {mu}} {yields} {nu}{sub e} oscillations with the Fermi National Accelerator Laboratory 8 GeV beam line, which produces a {nu}{sub {mu}} beam with an average energy of {approx} 0.8 GeV and an intrinsic {nu}{sub e} content of 0.4%. The neutrino detector is a 6.1 m radius sphere filled with CH{sub 2}, viewed by 1540 photo-multiplier tubes, and located 541 m downstream from the source. This work focuses on the estimation of systematic errors associated with the neutrino flux and neutrino interaction cross section predictions, and in particular, on constraining these uncertainties using in-situ MiniBooNE {nu}{sub {mu}} charged current quasielastic (CCQE) scattering data. A data set with {approx} 100,000 events is identified, with 91% CCQE purity. This data set is used to measure several parameters of the CCQE cross section: the axial mass, the Fermi momentum, the binding energy, and the functional dependence of the axial form factor on four-momentum transfer squared. Constraints on the {nu}{sub {mu}} and {nu}{sub e} fluxes are derived using the {nu}{sub {mu}} CCQE data set. A Monte Carlo study of a combined {nu}{sub {mu}} disappearance and {nu}{sub e} appearance oscillation fit is presented, which improves the {nu}{sub {mu}} {yields} {nu}{sub e} oscillation sensitivity of MiniBooNE with respect to a {nu}{sub e} appearance-only fit by 1.2-1.5{sigma}, depending on the value of {Delta}m{sup 2}.

Full Text Available Purpose: Many global organizations have aligned their strategy and operation via the ISO-based framework of integrated management system (IMS that allows them to merge quality, environment, health and safety management systems. In such context, having a robust electronic document management system (EDMS is essential, especially at global enterprises where a large amount of documents generated by processes flows through different work cultures. However, there is no "one-size-fits-all" design for EDMS because it depends on organizations' needs, size and resource allocation. This article discusses the interrelation between EDMS and IMS in order to suggest a best practice. Design/methodology/approach: This article methodologically based upon a qualitative, interpretivistic, longitudinal empirical study in a wind turbine factory. Findings and Originality/value: IMS improvement and effectiveness has been overlooking EDMS as a key factor in establishing appropriate technological support of the IMS processes. Rightful application of EDMS can further contribute to organizational learning, precision of documentation and cross-organisational collaboration. Research limitations/implications: Theorising on IMS needs a stronger perspective of the technological limitations and potentials of basing IMS on EDMS. Practical implications: IMS are complex systems involving a large number of administrative functions. EDMS provides a formal representation with automation potentials both heightening and securing document trustworthiness. Social implications: IMS has a tendency to stay with professionals, e.g. line managers and QA/QC/QMS professionals. The EDMS line of discussion suggests a broader inclusion. Originality/value: Researching IMS as a technological implementation is giving a better platform of aligning the IMS with other business processes and is bringing IMS closer to the operational activities within the enterprise.

Purpose: Many global organizations have aligned their strategy and operation via the ISO-based framework of integrated management system (IMS) that allows them to merge quality, environment, health and safety management systems. In such context, having a robust electronic document management system (EDMS) is essential, especially at global enterprises where a large amount of documents generated by processes flows through different work cultures. However, there is no "one-size-fits-all" design for EDMS because it depends on organizations' needs, size and resource allocation. This article discusses the interrelation between EDMS and IMS in order to suggest a best practice. Design/methodology/approach: This article methodologically based upon a qualitative, interpretivistic, longitudinal empirical study in a wind turbine factory. Findings and Originality/value: IMS improvement and effectiveness has been overlooking EDMS as a key factor in establishing appropriate technological support of the IMS processes. Rightful application of EDMS can further contribute to organizational learning, precision of documentation and cross-organisational collaboration. Research limitations/implications: Theorising on IMS needs a stronger perspective of the technological limitations and potentials of basing IMS on EDMS. Practical implications: IMS are complex systems involving a large number of administrative functions. EDMS provides a formal representation with automation potentials both heightening and securing document trustworthiness. Social implications: IMS has a tendency to stay with professionals, e.g. line managers and QA/QC/QMS professionals. The EDMS line of discussion suggests a broader inclusion. Originality/value: Researching IMS as a technological implementation is giving a better platform of aligning the IMS with other business processes and is bringing IMS closer to the operational activities within the enterprise.

The ATLAS detector has been used to search for high-mass states, such as new heavy charged gauge bosons, decaying to an electron plus missing energy. Based on pp collisions at a center of mass energy of 7TeV produced at the Large Hadron Collider, we present limits on the cross section times branching ratio of W' to e\

Photometers at 3914 A and 5577 A and an optical imager were part of an experimental package launched on a sounding rocket in the 1987 Wave Induced Particle Precipitation campaign at Wallops Island, Virginia. The objective was to measure lightning-induced electron precipitation (LEP) by means of its optical signature. This was the first attempt to measure LEP using rocket-borne optical instrumentation. Launch criteria included nearby thunderstorm activity and ground-based observations of Trimpi events. Lightning flashes are clearly discernible in the data. The photometer data was also characterized by large spin and precession modulations in the photon count rate, consistent with elevated steady particle fluxes in the northern portion of the instrument field of view. No evidence of LEP was observed by the photometers or onboard particle detectors (Arnoldy and Kintner, 1989). Analysis of the data has made it possible to place an upper limit of 0.0008 ergs/sq cm per sec on any burst precipitation energy flux that may have occurred during the rocket flight in the regions explored by the photometers.

Photometers at 3,914 angstrom and 5,577 angstrom and an optical imager were part of an experimental package launched on a sounding rocket in the 1987 Wave Induced Particle Precipitation (WIPP) campaign at Wallops Island, Virginia. The objective was to measure lightning-induced electron precipitation (LEP) by means of its optical signature. This was the first attempt to measure LEP using rocket-borne optical instrumentation. Launch criteria included nearby thunderstorm activity and ground-based observations of Trimpi events. Lightning flashes are clearly discernible in the data. The photometer data was also characterized by large spin and precession modulations in the photon count rate, consistent with elevated steady particle fluxes in the northern portion of the instrument field of view. No evidence of LEP was observed by the photometers or onboard particle detectors [Arnoldy and Kinter, 1989]. Analysis of the data has enabled the authors to place an upper limit of 8 x 10-4 ergs-cm-2-sec-1 on any burst precipitation energy flux that many have occurred during the rocket flight in the regions explored by the photometers

Vinyl copolymers with high radiation degradation sensitivity have been synthesized by copolymerizing vinylidene chloride (VDC), CH2 = CCl2, with methyl methacrylate (MMA), methacrylonitrile, methyl ?-chloroacrylate, and dimethyl itaconate using emulsion techniques. In addition, copolymers of methyl ?-chloroacrylate with methyl methacrylate and poly(?-chloroacrylonitrile) were studied. Introduction of vinylidene chloride into methyl methacrylate polymers caused a sharp increase in G/sub s/ even at relatively low VDC incorporation. Upon 29% VDC incorporation, the G/sub s/ value increased from 1.3 (homopolymer of MMA) to 3.4. G/sub s/ was found to be a linear function of copolymer content for several systems, but G/sub x/ was not. At higher VDC levels, the increase in G/sub s/ was countered by increases in G/sub x/. At lower VDC levels, G/sub x/ was suppressed below the values predicted by a linear G/sub x/ dependence on composition for such systems as VDC/MMA, MCA/MMA, and ?-chloroacrylonitrile/MMA. The VDC/MMA copolymer (29% VDC) gave a sensitivity of 4.0 x 10-5 C/cm2 to electron beam exposure using the 0% unexposed resist thickness loss criterion and is 2 to 3 times more sensitive than PMMA. Poly(?-chloroacrylonitrile) is a negative resist with a sensitivity of 5 x 10-5 C/cm2 using one-micron line images for testing

In micro-electrical discharge machining (micro-EDM), the discharge duration is ultra-short, and both the electric action and the thermal action by the discharge channel play important roles in the removing process of cathode material. However, in most researches on the machining mechanism of micro-EDM, only the thermal action is concerned. In this article, a combined atomistic-continuum modeling method in which the two-temperature model and the molecular dynamics simulation model are integrated is used to construct the simulation model for cathode in single-discharge micro-EDM process. With this simulation model, removing processes of Cu cathode material in micro-EDM under pure thermal action, pure electric action and the combination of them are investigated in a simulative way. By analyzing evolutions of temperature, stress and micro-structure of material as well as the dynamical behaviors of material in the removing process, mechanisms of the cathode material removal and crater formation are revealed. In addition, the removing process of cathode material under the combination of pure thermal action and pure electric action is compared with those under the two pure actions respectively to analyze the interactive effect between the thermal action and the electric action.

The 4th International Conference on Educational Data Mining (EDM 2011) brings together researchers from computer science, education, psychology, psychometrics, and statistics to analyze large datasets to answer educational research questions. The conference, held in Eindhoven, The Netherlands, July 6-9, 2011, follows the three previous editions…

In this study, we show the modification of the equation of motion of the electronic spin, which is derived by the quantum electron spin vorticity principle, by the effect of the electron electric dipole moment (EDM). To investigate the new contribution to spin torque by EDM, using first principle calculations, we visualize distributions of the local spin angular momentum density and local spin torque density of the YbF molecule on which the static electric field and magnetic field are applied at t = 0.

We propose an experiment to search for a permanent atomic electric-dipole moment (EDM) using laser-cooled $^1^7^1Yb$ atoms launched in an atomic fountain. A uniform B field sets the quantization axis, and the Ramsey separated-oscillatory-fields method is used to measure the Zeeman precession frequency of the atoms. Laser beams of appropriate polarization are used for preparation and detection in a given magnetic sublevel. The signature of an EDM is a shift in the Ramsey resonance correlated w...

High precision magnetometry is an essential requirement of the cryoEDM experiment at the Institut Laue-Langevin, Grenoble. We have developed a SQUID system for this purpose, however tests done in Oxford have been limited by the noisy electromagnetic environment inside our laboratory, therefore we have tested a smaller version of our prototype system in the very low noise environment at LSBB, Rustrel, France. We have studied the crosstalk between an array of parallel pick-up loops-where the field generated by a current in one loop is detected by the others. We monitored the magnetic field in the LSBB for over twelve hours; and after correcting these data for SQUID resets, and crosstalk, we compare it to the published values from nearby geomagnetic observatories. We have also measured the noise spectrum of our system and studied the effect that heating one of the pick-up loops into its conducting state has on the other, parallel loops.

The Standard Model of Particle Physics predicts a static electric dipole moment for the neutron (nEDM) breaking time reversal and parity symmetry. This prediction is several orders of magnitude below the current best experimental limit dn -26 ecm (90 % CL). We are currently setting up a new experiment at the new ultra-cold neutron (UCN) source at the Paul Scherrer Institut, Switzerland, with the ultimate goal to improve the sensitivity limit by almost two orders of magnitude. Besides passive and active compensation of external magnetic fields we will use an array of laser-driven optically-pumped atomic cesium magnetometers to control and monitor the stability and homogeneity of the magnetic field at the neutron precession chamber. A first array of eight cesium magnetometers was used to obtain the field distribution and stability over the neutron precession volume on a sub-pT level. The setup and first results are presented.

We perform a study on the predictions of electric-dipole moments (EDMs) of neutron, Mercury (Hg), Thallium (Tl), deuteron, and Radium (Ra) in the framework of next-to-minimal supersymmetric standard model (NMSSM) with CP-violating parameters in the superpotential and soft-supersymmetry-breaking sector. We confine to the case in which only the physical tree-level CP phase $(\\phi'_\\lambda - \\phi'_\\kappa)$, associated with the couplings of the singlet terms in the superpotential and with the vacuum-expectation-values (VEVs), takes on a nonzero value. We found that the one-loop contributions from neutralinos are mostly small while the two-loop Higgs-mediated contributions of the Barr-Zee (BZ) type diagrams dominate. We emphasize a scenario motivated by electroweak baryogenesis.

In 1985 Simpson reported evidence for the emission of a 17 keV mass neutrino in a small fraction of tritium beta decays. An experimental controversy ensued in which a number of both positive and negative results were reported. The beta spectrum of {sup 14}C was collected in a unique {sup 14}C-doped planar germanium detector and a distortion was observed that initially confirmed Simpson`s result. Further tests linked this distortion to a splitting of the collected charge between the central detector and the surrounding guard ring in a fraction of the events. A second {sup 14}C measurement showed no evidence for emission of a 17 keV mass neutrino. In a related experiment, a high statistics electron-capture internal-bremsstrahlung photon spectrum of {sup 55}Fe was collected with a coaxial germanium detector. A local search for departures from a smooth shape near the endpoint was performed, using a second-derivative technique. An upper limit of 0.65% (95% C.L.) for the mixing Of a neutrino in the mass range 5--25 keV was established. The upper limit on the mixing of a 17 keV mass neutrino was 0.14% (95% C.L.).

We show that in the MSSM without R-parity symmetry there are no new contributions to electron and neutron electric dipole moments (EDMs) at 1-loop induced by the R-parity violating Yukawa couplings. Non-zero EDMs for the electron and neutron first arise at the 2-loop level. As an example we estimate the contribution of a two-loop graph which induces electronEDMs. On the other hand, we show that the (Majorana) neutrino electric and magnetic transition moments are non-zero even at the 1-loop level. Constraints on the R-parity violating couplings are derived from the existing bounds on the neutrino dipole moments. (author)

In the micro-machining and MEMS industry, micro-Electrical discharge machining (?-EDM) is an important process. In this paper, the Taguchi design approach has been employed to investigate the micro-EDM parameters in order to achieve the highest Material Removal Rate (MRR), good surface quality and low Tool Wear Rate (TWR) while machining Ni-Ti based Shape Memory Alloy (SMA). Based on these investigations, it has been observed that MRR is highly influenced by capacitance, discharge voltage an...

The machining parameter settings installed at CNC EDM machines are developed under optimum process conditions. Standard workpiece and electrode materials are used traditionally by machine manufacturers to establish the EDM parameter settings. However, this is not the usual situation of the tooling industry, where many different grades of workpiece and tool electrode materials are used. Consequently, the customers are required to develop their own process parameters, which normally demand many...

Energies, transition rates, and electron electric-dipole-moment (EDM) enhancement factors are calculated for low-lying states of Ce IV and Pr V using relativistic many-body perturbation theory. This study is related to recent investigations of the more complicated Gd IV ion, which is promising for electronEDM experiments. The ions Ce IV and Pr V both have a single valence electron, permitting one to carry out reliable ab initio calculations of energy levels, transition rates, and other atomic properties using well-developed computational methods

A search for the top quark in {ital {bar p}p} collisions at a center-of-mass energy of 1.8 TeV using the Collider Detector at Fermilab is described. A study of events selected by requiring an energetic electron, missing transverse energy, and two or more jets excludes at 95% confidence level the standard-model production and decay of {ital t{bar t}} pairs if the top-quark mass is between 40 and 77 GeV/{ital c}{sup 2}. The observed electron + multijet data are consistent with {ital W}-boson production.

In the process of EDM, due to the electrical current, very small bubbles are created within the gap. These bubbles are connected to each other and generate a single bubble. The vapor bubble continues to grow until it finally collapses to small bubbles. The bubble behavior can be ascertained on the distribution of the pressure in the dielectric fluid around the bubble. In this paper, velocity fields and pressure distribution in the dielectric fluid around the bubble that is generated in the process of EDM are investigated numerically. The tool and the workpiece are assumed as two parallel rigid boundaries with dielectric liquid between them. The boundary integral equation method is applied for the numerical solution of the problem. This study can lead to better understanding of the bubble importance in the performance of the electrical discharge machining process.

Full text: The neutron electric dipole moment (nEDM) experiment at the Paul Scherrer Institut (PSI) measures the Larmor precession frequencies of ultracold neutrons (UCN) in parallel and antiparallel magnetic and electric fields. Nuclear spin polarized 199Hg atoms are utilized as cohabiting magnetometer and monitor changes of the magnetic field within the same volume as the UCN. Due to the different velocities of the two species and the effect of gravity, the magnetic field of the precession volume is sampled differently by UCN (?4 m/s) and 199Hg ((?170 m/s), respectively. Thus, in presence of vertical magnetic field gradients, the two species will systematically measure different fields. I will present measurements of the ratio of the two precession frequencies as function of vertical gradients performed with the nEDM apparatus in 2012. This quantity is an important tool to investigate systematic effects and also physical properties of the involved species. (author)

In this study on-machine measurement-assisted techniques are utilized in combination with micro-EDM to successfully machine intricate micro-parts. Two measurement approaches, automatic optical inspection (AOI) and critical contact measurement (CCM), are used on a previously built machine tool. AOI acquires the image from the contour of the machined workpiece and further processes the image to determine the finish allowance. CCM measures on-line the consumption of the microelectrode to create an accurate compensation rate. These two non-contact measurement techniques facilitate on-machine error detection and re-machining during micro-EDM. Significant work efficiency and preservation of machining accuracy are gained by having the workpiece and tool remain in place throughout machining procedures. A micro-probe with a diameter of 30 µm and a micro 3D engraving mold on a small tungsten steel ball are perfectly fabricated and verified, respectively

Full Text Available In this study the optimization of the Electrical Discharge Machining (EDM process with multiple performance characteristics based on orthogonal array with the Grey relational analysis was studied. The Grey relational analysis theory was used to resolve the complicated interrelationships among the multiple performance characteristics. In the present study, attempt was made to find the optimal machining conditions under which a blind-hole can be drilled using a multihole electrode. The Taguchi method was used to determine the relations between machining parameters and process characteristics. In this study, the machining parameters, namely electrode polarity, discharge current, pulse on time, pulse off time and dielectric pressure were optimized with considerations of multiple performance characteristics including machining time, electrode wear and surface roughness. Experimental results showed that machining performance in the EDM process can be improved effectively through this approach.

An analysis of the neutron EDM and of the electronEDM in minimal N=1 supergravity unification with two CP-violating phases is given. For the neutron the analysis includes the complete one loop gluino, chargino, and neutralino exchange diagrams for the electric dipole and the chromoelectric dipole operators, and also the contribution of the purely gluonic dimension-six operator. It is shown that there exist significant regions in the six-dimensional parameter space of the model where cancellations between the gluino and the chargino exchanges reduce the electric and the chromoelectric contributions, and further cancellations among the electric, the chromoelectric, and the purely gluonic parts lead to a dramatic lowering of the neutron EDM sometimes below the electronEDM value. This phenomenon gives a new mechanism, i.e., that of internal cancellations, for the suppression of the neutron EDM in supersymmetric theories. The cancellation mechanism can significantly reduce the severe fine-tuning problem associated with CP-violating phases in SUSY and SUGRA unified models. copyright 1997 The American Physical Society

In this study the optimization of the Electrical Discharge Machining (EDM) process with multiple performance characteristics based on orthogonal array with the Grey relational analysis was studied. The Grey relational analysis theory was used to resolve the complicated interrelationships among the multiple performance characteristics. In the present study, attempt was made to find the optimal machining conditions under which a blind-hole can be drilled using a multihole electrode. The T...

Full Text Available Electrical Discharge Machining (EDM is a non conventional machining process, where electrically conductive materials are machined by using a precisely controlled spark that occurs between an electrode and a work piece in the presence of a dielectric fluid. It has been a demanding research area to model and optimize the EDM process in the present scenario. In this work a neural network model is presented for predictions of material removal rate (MRR & tool wear rate (TWR in die sinking electrical discharge machining (EDM process for American Iron and Steel Institute 1045 tool steel with copper electrode.Experimentation has been carried out on EDM of AISI 1045 tool Steel. The experimental results have been used to train ANN using Back-Propagation Algorithm which gives the optimum value of the performance parameters like Material Removal Rate (MRR and Tool Wear Rate (TWR based on the influence of various electrode materials and processing parameters such as Gap Voltage, Peak Current, Pulse on time and Pulse off time. According to the correlation coefficients diagram it was concluded that the ANN tool gives us the best possible predictions for the data we have trained.Also we are getting ANN MRR results very much closer to our experimental MRR values.This shows the values that are very much possible to correlate amongst one another apart from taking experiments and finally the values of experimental TWR and predicted TWR are nearly correlating with one another.This shows that the ANN can be trained enough to give us close results by predicting the values.

Mass fabrication of polymer micro components with high aspect ratio micro-structures requires high performance micro tools allowing the use of low cost replication processes such as micro injection moulding. In this regard an innovative process chain, based on a combination of micro electrical discharge machining (mu EDM) of a silicon substrate, electroforming and selective etching was used for the manufacturing of a micro tool. The micro tool was employed for polymer replication by means of the injection moulding process.

A new method for the detection of the electron electric dipole moment (EDM) using a solid is described. The method involves the measurement of a voltage induced across the solid by the alignment of the sample's magnetic dipoles in an applied magnetic field, H. A first application of the method to GdIG has resulted in a limit on the electronEDM of 5 x 10(-24)e cm, which is a factor of 40 below the limit obtained from the only previous solid-state EDM experiment. The result is limited by the imperfect discrimination of an unexpectedly large voltage that is even upon the reversal of the sample magnetization. PMID:16384457

The usage of electrical discharge machining (EDM) is increasing gradually owing to its capability to cut precisely, geometrically complex material regardless hardness. Many process parameters greatly affect the EDM performance and complicated mechanism of the process result the lag of established theory. Hence, it becomes important to select the proper parameter set for different machining stages in order to promote efficiency. In view of these barriers, it is attempted to establish a model which can accurately predict the material removal rate (MRR) of titanium alloy by correlating the process parameter. Effect of the parameters on MRR is investigated as well. Experiment is conducted utilizing the graphite electrode maintaining negative polarity. Analysis and modelling is carried out based on design of experiment as well as response surface methodology. The agreeable accuracy is obtained and thus the model can become a precise tool setting the EDM process cost effective and efficient. Moreover, high ampere, short pulse-off time and low servo-voltage combined with about 250 ?s pulse-on time generate the highest MRR.

Full Text Available EDM machining is used for very hard and complex cutting of conducting materials with higher surface finish and close dimensions. EDM process parameters are affected by both electrical and non electrical parameters. In these paper cutting of hard material high carbon high chromium (HCHcr D3 steel is done on electro discharge machine with copper as cutting tool electrode. This paper presents a work on the performance parameter optimization for material removal rate (MRR and electrode wear rate (EWR. There are electrical and non electrical factors which influences MRR and EWR such as voltage ,current pulse on time , pulse off time , dielectric fluid material , flushing pressure, tool rotation etc. In theses paper both the electrical factors and non electrical factors has been focused which governs MRR, EWR and there optimization. Paper is based on Design of experiment and optimization of EDM process parameters .The technique used is Taguchi technique which is a statistical decision making tool helps in minimizing the number of experiments and the error associated with it. The research showed that the peak current has significant effect on material removal rate.

Abrasive powder-mixed electrical discharge machining (APM-EDM), a hybrid manufacturing process involving the use of a dielectric fluid mixed with abrasive powder, combines the benefits of mechanical and thermal interactions. The aim of this article is to use a new approach of performance evaluation, gray relational analysis (GRA), to evaluate the effectiveness of optimizing multiple performance characteristics of APM-EDM of 6061Al/Al2O3p/20p aluminum matrix composites (AMCs). The considered process parameter includes the seven control factors namely pulse current (A), pulse ON time (?s), duty cycle (%), gap voltage (V), time interval of tool lift (s), abrasive powder concentration (g/L), abrasive particle size (?m), and a noise factor, aspect ratio (shape of tool electrode). The combination of L18 (21 × 37) orthogonal array design of experiment with GRA enables to determine the optimal parameters for multiple responses. GRA is used to obtain a single performance index, gray relational grade through gray relational coefficient to optimize the APM-EDM process with lower tool wear rate, surface roughness, and higher material removal rate. In addition, analysis of variance (ANOVA) for the GRC is also utilized.

In this study, a new affinity high-performance liquid chromatography (HPLC) stationary phase suitable for protein separation was synthesized. In the first stage of the synthesis, uniform porous poly(2-hydroxyethyl methacrylate-co-ethylene dimethacrylate), poly(HEMA-co-EDM), beads 6.2 mum in size were obtained. Homogeneous distribution of hydroxyl groups in the bead interior was confirmed by confocal laser scanning microscopy. The plain poly(HEMA-co-EDM) particles gave very low non-specific protein adsorption with albumin. The selected dye ligand Cibacron blue F3G-A (CB F3G-A) was covalently linked onto the beads via hydroxyl groups. In the batch experiments, albumin adsorption up to 60 mg BSA/g particles was obtained with the CB F3G-A carrying poly(HEMA-co-EDM) beads. The affinity-HPLC of selected proteins (albumin and lysozyme) was investigated in a 25 mm x 4.0-mm inner diameter column packed with CB F3G-A carrying beads and both proteins were successfully resolved. By a single injection, 200 mug of protein was loaded and quantitatively eluted from the column. The protein recovery increased with increasing flow rate and salt concentration of the elution buffer and decreased with the increasing protein feed concentration. During the albumin elution, theoretical plate numbers up to 30,000 plates/m were achieved by increasing the salt concentration. PMID:16231138

The usage of electrical discharge machining (EDM) is increasing gradually owing to its capability to cut precisely, geometrically complex material regardless hardness. Many process parameters greatly affect the EDM performance and complicated mechanism of the process result the lag of established theory. Hence, it becomes important to select the proper parameter set for different machining stages in order to promote efficiency. In view of these barriers, it is attempted to establish a model which can accurately predict the material removal rate (MRR) of titanium alloy by correlating the process parameter. Effect of the parameters on MRR is investigated as well. Experiment is conducted utilizing the graphite electrode maintaining negative polarity. Analysis and modelling is carried out based on design of experiment as well as response surface methodology. The agreeable accuracy is obtained and thus the model can become a precise tool setting the EDM process cost effective and efficient. Moreover, high ampere, short pulse-off time and low servo-voltage combined with about 250 ?s pulse-on time generate the highest MRR.

This paper demonstrates a novel fabrication process using electro-discharge-machining (EDM) combined with co-deposited Ni-diamond composites to build a unique micro-spherical diamond tool. A micro tool is made by a hybrid process including wire electro-discharge grinding, EDM spherical forming, electrochemical machining and co-deposition. Tungsten carbide material is used as the tool substrate. The influence of EDM spherical forming and co-deposition parameters on the tool geometry is presented. The experimental result shows a unique micro-spherical diamond tool can be successfully built with suitable spherical forming parameters that are a peak current of 3 A, pulse duration of 40 µs and spindle rotational speed of 0 rpm in the air, and in Ni-diamond co-deposition are a current density of 7 A dm?2, diamond particle size of 3 µm, diamond particle concentration of 10 g l?1 and rotational speed of 15 rpm. When using this method, the micro tool has a better geometric shape, uniform particle distribution and suitable particle adhesion quantity. The tool is tested to machine a mold provided with a micro-spherical cavity in a high nickel alloy

This experimental work is an attempt to investigate the performance of Copper electrode when EDM of Nickel Based Super Alloy, Inconel 718 is at higher peak current and pulse duration. Peak current, Ip and pulse duration (pulse on-time), ton are selected as the most important electrical pulse parameters. In addition, their influence on material removal rate (MRR), electrode wear rate (EWR), and surface roughness (Ra) are experimentally investigated. The ranges of 10 mm diameter of Copper electrode are used to EDM of Inconel 718. After the experiments, MRR, EWR, and Ra of the machined surfaces need to be measured in order to evaluate the performance of the EDM process. In order to obtain high MRR, higher peak current in range of 20A to 40A and pulse duration in range of 200?s to 400?s were used. Experimental results have shown that machining at a highest peak current used of 40A and the lowest pulse duration of 200?s used for the experiment yields the highest material removal rate (MRR) with value 34.94 mm3/min, whereas machining at a peak current of 20A and pulse duration of 400?s yields the lowest electrode wear rate (EWR) with value -0.0101 mm3/min. The lowest surface roughness (Ra) is 8.53 ?m achieved at a lowest peak current used of 20A and pulse duration of 200?s.

We study the electric dipole moments(EDM) of the neutron and the electron in the two-Higgs-doublet model, in the case that CP symmetry is violated maximally in the neutral Higgs sector. We take account of the Weinberg's operator O_{3g}=GG\\t G as well as the operator O_{qg}=\\bar q\\sigma\\tilde Gq for the neutron, and the Barr-Zee diagrams for the electron. It is found that the predicted neutron EDM could be considerably reduced by the destructive contribution of the two Higgs scalars to get the lower value than the experimental bound. As to the electronEDM, the predicted value is smaller in one order than the experimental one.

Based on recent experiences with respect to JETT (J lowbar -E lowbar valuation on T lowbar ensile T lowbar est) several materials were measured to investigate the potential of this novel technique with the aim to determine the fracture toughness of materials. The investigated materials covered a wide field of toughness levels ranging from ?2 MPa?m to ?300 MPa?m. These materials were as follows; OFHC annealed copper, CuNiSi, sintered NdFeB, FeCo, 9Ni steel, Al 6061-T6, wrought 316LN, and modified Type 316LN cast steels. The tests comprised measurements of EDM notched round bars as well as double edged flat tensile specimens between 300 K and 7 K. Wherever possible the tests were cross checked with ASTM standard compact tension or single edged notched specimens using the standard procedures. Main attention was paid to seek a solution towards a realistic integration path focusing the materials fracture point, comprising tests with high ductility and medium toughness materials represented by copper and copper alloys. Scanning electron microscopic investigations at the notch tip of loaded and subsequently unloaded specimens at the maximum load position could reveal the crack initiation at the notch tip immediately after the start of necking. A concept was driven for reliable evaluation and estimation of the materials critical J and the related fracture toughness

Gadolinium iron garnet (Gd3Fe5O12) ferrite ceramic maintains its high magnetic susceptibility down to cryogenic temperatures: our measurements at 4 K give ?=75. This gives rise to an enhancement of material magnetization that would be induced by effects such as violation of local Lorentz invariance, or orientation of permanent electric dipole moments caused by an applied electric field. Such magnetization can be detected with DC SQUID magnetometers. Magnetic noise measurements with SQUIDs at 4 K indicate that the EDM sensitivity on the level of 10-28e.cm is achievable after ten days of averaging.

We present a search for excited and exotic electrons (e*) decaying to an electron and a photon, both with high transverse momentum. We use 202 pb-1 of data collected in p(bar p) collisions at ?s = 1.96 TeV with the CDF II detector. No signal above standard model expectation is seen for associated ee* production. We discuss the e* sensitivity in the parameter space of the excited electron mass Me* and the compositeness energy scale ?. In the contact interaction model, we exclude 132 GeV/c2 e* 2 for ? = Me* at 95% confidence level (C.L.). In the gauge-mediated model, we exclude 126 GeV/c2 e* 2 at 95% C.L. for the phenomenological coupling f/? ? 10-2 GeV-1

A non-zero neutron electric dipole moment (nEDM) would violate time and parity reversal symmetry. Its detection would be a major discovery, but also improving the current upper limit of 2.9.10-26 e.cm constrains theories beyond the Standard Model of Particle Physics, such as supersymmetry. An apparatus is being set up at the Paul Scherrer Institut in Switzerland in order to improve the current sensitivity by two orders of magnitude. This shall be achieved by increasing statistics with a new powerful ultracold neutron source, and by improving control on systematics. The main sources for systematic errors are fluctuations of magnetic field inside the experimental volume. These might be introduced from the environment and shall be actively compensated for by implementing a surrounding field compensation (SFC) coil system. In this talk the working principle of the SFC and its commissioning are presented. First results on the investigation of the magnetic environment of the experiment and the effect of the SFC on it are included.

The Standard Model (SM) of Particle Physics predicts a static electric dipole moment for the neutron (nEDM), breaking time reversal and parity symmetry. This prediction is several orders of magnitude below the current best experimental limit dn -26ecm (90% CL). An experiment at the new ultra-cold neutron (UCN) source at the Paul Scherrer Institut (PSI), Switzerland, aims at a factor five improved sensitivity. Ultimately, the collaboration pursues the goal to improve the sensitivity by another order of magnitude. The experiment employs Ramsey's method of separated oscillatory fields to detect a Larmor frequency shift for the UCN in a parallel and an anti-parallel configuration of a magnetic and an electric field. The transmission modulation of a circularly polarized light beam is used to detect the spin precession of a spin polarized ensemble of 199Hg atoms in the same volume as the UCN and thus to measure the applied magnetic field (?1?T). Currently we reach a precision of 50 fT over 100 s. I present recently achieved improvements of this co-magnetometer and ideas how to further improve this magnetometer by using a laser as light source.

The operating control parameters of injection flushing type of electrical discharge machining process on stainless steel 304 workpiece with copper tools are being optimized according to its individual machining characteristic i.e. surface roughness (SR). Higher SR during EDM machining process results for poor surface integrity of the workpiece. Hence, the quality characteristic for SR is set to lower-the-better to achieve the optimum surface integrity. Taguchi method has been used for the construction, layout and analysis of the experiment for each of the machining characteristic for the SR. The use of Taguchi method in the experiment saves a lot of time and cost of machining the experiment samples. Therefore, an L18 Orthogonal array which was the fundamental component in the statistical design of experiments has been used to plan the experiments and Analysis of Variance (ANOVA) is used to determine the optimum machining parameters for this machining characteristic. The control parameters selected for this optimization experiments are polarity, pulse on duration, discharge current, discharge voltage, machining depth, machining diameter and dielectric liquid pressure. The result had shown that the lower the machining diameter, the lower will be the SR.

Full Text Available The purpose of this study was to develop a novel measurement method using a machine vision system. Besides using image processing techniques, the proposed system employs a detection line algorithm that detects the tool electrode length and drilling depth of a workpiece accurately and effectively. Different boundaries of areas on the tool electrode are defined: a baseline between base and normal areas, a ND-line between normal and drilling areas (accumulating carbon area, and a DD-line between drilling area and dielectric fluid droplet on the electrode tip. Accordingly, image processing techniques are employed to extract a tool electrode image, and the centroid, eigenvector, and principle axis of the tool electrode are determined. The developed detection line algorithm (DLA is then used to detect the baseline, ND-line, and DD-line along the direction of the principle axis. Finally, the tool electrode length and drilling depth of the workpiece are estimated via detected baseline, ND-line, and DD-line. Experimental results show good accuracy and efficiency in estimation of the tool electrode length and drilling depth under different conditions. Hence, this research may provide a reference for industrial application in EDM drilling measurement.

The operating control parameters of injection flushing type of electrical discharge machining process on stainless steel 304 workpiece with copper tools are being optimized according to its individual machining characteristic i.e. surface roughness (SR). Higher SR during EDM machining process results for poor surface integrity of the workpiece. Hence, the quality characteristic for SR is set to lower-the-better to achieve the optimum surface integrity. Taguchi method has been used for the construction, layout and analysis of the experiment for each of the machining characteristic for the SR. The use of Taguchi method in the experiment saves a lot of time and cost of machining the experiment samples. Therefore, an L18 Orthogonal array which was the fundamental component in the statistical design of experiments has been used to plan the experiments and Analysis of Variance (ANOVA) is used to determine the optimum machining parameters for this machining characteristic. The control parameters selected for this optimization experiments are polarity, pulse on duration, discharge current, discharge voltage, machining depth, machining diameter and dielectric liquid pressure. The result had shown that the lower the machining diameter, the lower will be the SR.

Full Text Available Analyzing 60 questionnaires collected, it was determined that the preliminary web and search tool skills of students studied were lesser than average (37.5%. Most of the members of the population studied, generally considered themselves as being “veterans”, i.e. a person that is successful in finding the needed information but who most of the time needs assistance. Students were most familiar with Google and Yahoo search engines, and with Elsevier specialized database. Search Engines and Database usage were also investigated. The average employment of the Boolean operators was 34.7%, with “+” operator having the highest and “-“ operator having the least usage. Google advanced search and Elsevier database were most frequently used.

A Cs fountain electron electric dipole moment (EDM) experiment using electric-field quantization is demonstrated. With magnetic fields reduced to 200 pT or less, the electric field lifts the degeneracy between hyperfine levels of different|mF| and, along with the slow beam and fountain geometry, suppresses systematics from motional magnetic fields. Transitions are induced and the atoms polarized and analyzed in field-free regions. The feasibility of reaching a sensitivity to an electronEDM of 2 x 10 exp(-50) C-m [1.3 x 10 exp(-29) e-cm] in a cesium fountain experiment is discussed.

We report the most sensitive direct search for pair production of fourth-generation bottomlike chiral quarks (b') each decaying promptly to tW. We search for an excess of events with an electron or muon, at least five jets (one identified as due to a b or c quark), and an imbalance of transverse momentum by using data from pp collisions collected by the CDF II detector at Fermilab with an integrated luminosity of 4.8??fb(-1). We observe events consistent with background expectation, calculate upper limits on the b' pair-production cross section (?(bb')) ?30??fb for m(b') > 375??GeV/c2), and exclude m(b') < 372??GeV/c2 at 95% confidence level assuming a 100% branching ratio of b' to tW. PMID:21561183

Electronics Theory and Practice introduces the key areas of analog electronics through practicals, worked examples and concise explanations. The author is a senior lecturer at De Montfort University and his approach is a proven way of teaching the essentials of electronics to groups with a variety of academic backgrounds. This is an ideal text for first year modules and HNC/D units - comprehensive, concise and affordable.

Recently the Eu$_{0.5}$Ba$_{0.5}$TiO$_{3}$ solid was suggested as a promising candidate for experimental search of the electron electric dipole moment. To interpret the results of this experiment one should calculate the effective electric field acting on an unpaired (spin-polarized) electrons of europium cation in the crystal because the value of this field cannot be measured experimentally. The Eu$^{++}$ cation is considered in the paper in the uniform external electric field \\Eext\\ as our first and simplest model simulating the state of europium in the crystal. We have performed high-level electronic structure correlation calculation using coupled clusters theory (and scalar-relativistic approximation for valence and outer core electrons at the molecular pseudopotential calculation stage that is followed by the four-component spinor restoration of the core electronic structure) to evaluate the enhancement coefficient $K= \\Eeff/\\Eext$ (where \\Eext\\ is the applied external electric field and \\Eeff\\ is the in...

Full Text Available SciELO Brazil | Language: English Abstract in english The machining parameter settings installed at CNC EDM machines are developed under optimum process conditions. Standard workpiece and electrode materials are used traditionally by machine manufacturers to establish the EDM parameter settings. However, this is not the usual situation of the tooling i [...] ndustry, where many different grades of workpiece and tool electrode materials are used. Consequently, the customers are required to develop their own process parameters, which normally demand many experimental tests. According to the aforementioned argument an experimental investigation on the EDM of AISI P20 tool steel under finish machining has been carried out. The tests were performed with graphite and copper as tool electrodes. Important EDM electrical parameters that influence the process performance were investigated. The measured technological outputs were the material removal rate Vw, volumetric relative wear J and workpiece surface finish Ra . The main conclusions can be summarized as follows: the best results for material removal rate Vw were reached when EDM with negative graphite electrodes. Graphite and copper tools presented similar results of Vw for positive polarity. For graphite and copper tools the lowest values of volumetric relative wear were achieved for positive polarity. The best surface roughness Ra was obtained for copper electrodes under negative polarity.

Full Text Available The machining parameter settings installed at CNC EDM machines are developed under optimum process conditions. Standard workpiece and electrode materials are used traditionally by machine manufacturers to establish the EDM parameter settings. However, this is not the usual situation of the tooling industry, where many different grades of workpiece and tool electrode materials are used. Consequently, the customers are required to develop their own process parameters, which normally demand many experimental tests. According to the aforementioned argument an experimental investigation on the EDM of AISI P20 tool steel under finish machining has been carried out. The tests were performed with graphite and copper as tool electrodes. Important EDM electrical parameters that influence the process performance were investigated. The measured technological outputs were the material removal rate Vw, volumetric relative wear J and workpiece surface finish Ra . The main conclusions can be summarized as follows: the best results for material removal rate Vw were reached when EDM with negative graphite electrodes. Graphite and copper tools presented similar results of Vw for positive polarity. For graphite and copper tools the lowest values of volumetric relative wear were achieved for positive polarity. The best surface roughness Ra was obtained for copper electrodes under negative polarity.

Full Text Available SciELO Brazil | Language: English Abstract in english The machining parameter settings installed at CNC EDM machines are developed under optimum process conditions. Standard workpiece and electrode materials are used traditionally by machine manufacturers to establish the EDM parameter settings. However, this is not the usual situation of the tooling i [...] ndustry, where many different grades of workpiece and tool electrode materials are used. Consequently, the customers are required to develop their own process parameters, which normally demand many experimental tests. According to the aforementioned argument an experimental investigation on the EDM of AISI P20 tool steel under finish machining has been carried out. The tests were performed with graphite and copper as tool electrodes. Important EDM electrical parameters that influence the process performance were investigated. The measured technological outputs were the material removal rate Vw, volumetric relative wear J and workpiece surface finish Ra . The main conclusions can be summarized as follows: the best results for material removal rate Vw were reached when EDM with negative graphite electrodes. Graphite and copper tools presented similar results of Vw for positive polarity. For graphite and copper tools the lowest values of volumetric relative wear were achieved for positive polarity. The best surface roughness Ra was obtained for copper electrodes under negative polarity.

A search for parity violating effects in the inelastic scattering of polarized electrons off an unpolarized deuterium target at 19.4 GeV has recently been performed at SLAC. Using the 20-GeV/c and 8-GeV/c spectrometers, two kinematical points with Q2 values of 1.2 GeV/c2 and 4.2 GeV/c2, respectively, have been measured. Statistical accuracy of the measurements approaches the level of the weak interactions. Systematic errors are still being studied. Techniques to measure and control systematic errors and the present status of the data analysis are discussed

We present the results of a search for Wprime boson decaying to electron-neutrino pairs in pbarp collisions at a center-of-mass energy of 1.96 TeV, using a data sample corresponding to 205 pb^-1 of integrated luminosity collected by the CDF II detector at Fermilab. We observe no evidence for this decay mode and set limits on the production cross section times branching fraction, assuming the neutrinos from Wprime boson decays to be light. If we assume the manifest left-right symmetric model, we exclude a Wprime boson with mass less than 788 GeV/c^2 at the 95% confidence level.

Full Text Available Purpose: This work models the Ra parameter as a function of current intensity (I, the electrode material and the work material. The surface is directly related to the average intensity (I during machining. If the intensity is increased to 25 A, the roughness of the room rises dramatically to 15 microns.Design/methodology/approach: Machining with a copper tool produces a better surface than can be achieved by a graphite tool. Copper tool machining has been performed in an efficient way, eliminating the necessity of a large number of experiments. The statistical processing of the results enabled development of a mathematical model to calculate the machined surface quality according to the parameters of the cut used.Findings: The mathematical model, which precisely determines surface roughness, is a tool for cutting parameters and has been obtained by the experimental design method. It enables a high quality range in analysing experiments and achieving optimal exact values. A relatively small number of designed experiments are required to generate useful information and thus develop the predictive equations for surface roughness. Depending on the surface roughness data provided by the experimental design, a first-order predicting equation has been developed.Practical implications: The experimental design was proposed for predicting the relative importance of various factors (composition of the steels and electrical discharge machining (EDM processing conditions to obtain efficient pieces. This model gives detailed information on the effect of parameters of cut on the surface roughness.Originality/value: Experimental data was compared with modelling data to verify the adequacy of the model prediction. As shown in this work, the factor of intensity has the most important influence on the surface roughness.

In a previous work, we showed that it is possible to detect keV scale sterile neutrino dark matter ?s in a ? decay experiment using radioactive sources such as T3 or Ru106. The signals of this dark matter candidate are monoenergetic electrons produced in the neutrino capture process ?s+ N'?N+e-. These electrons have energy greater than the maximum energy of the electrons produced in the associated decay process N'?N+e-+? ¯e. Hence, signal electron events are well beyond the end point of the ? decay spectrum and are not polluted by the ? decay process. Another possible background, which is a potential threat to the detection of ?s dark matter, is the electron event produced by the scattering of solar neutrinos with electrons in target matter. In this article, we study in detail this possible background and discuss its implications for the detection of keV scale sterile neutrino dark matter. In particular, bound state features of electrons in Ru atoms are considered with care in the scattering process when the kinetic energy of the final electron is the same order of magnitude of the binding energy.

Two dosimeters, positioned on the chest and back, could provide sufficient information for reasonable estimation of effective dose (E) for most exposure situations, excluding the possibility of significant underestimation of effective dose. Use of these two dosimeters with a suitable algorithm could not only solve the underestimation problem of the single-dosimeter approach, but could also alleviate the disadvantages of the multiple-dosimeter approach. However, it has not yet been confirmed experimentally whether the two-dosimeter approach estimates effective dose adequately or merely conservatively. Two-dosimeter algorithms were developed by simplified geometry and Monte Carlo simulations because it was not able to measure the effective dose directly. In this present study, the two-dosimeter approach was experimentally validated with a measurement system called pseudo Effective Dose Measurement System (EDMS) which is developed in the present study to measure effective dose. This system comprises 38 very small isotropic-responding high-sensitivity MOSFET dosimeters in an ATOM adult male phantom supported by 3D image-based Monte Carlo simulation technology to obtain accurate values of organ doses, effective dose and other quantities of interest. The EDMS is portable and very easy to use in the field and it measures the doses on a real-time basis. Because the ATOM adult male phantom has only 4 organs including bone, soft tissue, brain, and lungs, the other organs necessary for calculation of effective dose were defined with reference to the MIRD5 mathematical phantom. The numbers and locations of the MOSFET dosimeters were determined carefully after considering the tissue weighting factors, shapes and volumes of the organs. Each organ dose was determined by the 1-6 point-wise absorbed doses measured with the MOSFET dosimeters. The MOSFET dosimeter had been selected in the present study because it is very small and can measure radiation dose on a real-time basis. The MOSFET dosimeter, however, made mainly of silicon and epoxy, shows some energy dependence for low-energy photons. That is, when used in a phantom, it overestimates absorbed doses due to the existence of low-energy scattered photons. The MOSFET dosimeter shows some degree of angular dependence as well. Therefore, for accurate measurement of organ and tissue doses, the present study determined, by Monte Carlo simulations with the Monte Carlo N-Particle Transport Code System (MCNPX), the relative response (to tissue dose) of the MOSFET dosimeter, and thereby the dose correction factors, at various dosimeter locations in the ATOM adult male phantom. The MOSFET dosimeter is controlled by the MOSFET AutoSenseTM Dose Verification System and all messages generated by the system are recorded in 'MsgHistoryOnCOM.txt'. A data process program, which can read the text file and calculate organ doses, E and other dose quantities was developed in C++. The 2007 recommendation of International Commission on Radiological Protection (ICRP 103) uses organ-averaged doses, called equivalent doses, and tissue weighting factors to calculate effective dose. The recommendation also designated two ICRP reference phantoms to be used in calculation of equivalent doses and effective dose. However, the EDMS measures effective dose using an ATOM adult male phantom and 38 MOSFET dosimeters, which results in an approximate measurement of effective dose. Therefore, in the present study, the error of effective dose measurement was determined by Monte Carlo simulations using the ICRP reference phantoms and the ATOM-MIRD hybrid phantoms. The ATOMMIRD hybrid phantoms are developed in the present study by combining the CT images of the ATOM phantoms (for lungs, bone, brain, and skin) and the MIRD5 mathematical phantom (for the other organs). The effective dose calculated by the ICRP reference phantoms and the ATOM-MIRD hybrid phantoms showed good agreement for high energy photon beams (?100 keV) for all irradiation geometries. The maximum difference was 35%, which occurs for the 30 keV photon beam i

The MiniBooNE Collaboration reports first results of a search for {upsilon}{sub e} appearance in a {upsilon}{sub {mu}} beam. With two largely independent analyses, we observe no significant excess of events above background for reconstructed neutrino energies above 475 MeV. The data are consistent with no oscillations within a two neutrino appearance-only oscillation model.

We report the first results of ab initio relativistic correlation calculation of the effective electric field on the electron, Eeff, in the ground state of the HI+ cation. This value is required for interpretation of the suggested experiment on the search for the electron electric dipole moment. The generalized relativistic effective core potential, Fock-space relativistic coupled cluster with single and double cluster amplitudes (RCC-SD), and spin-orbit direct configuration interaction (SODCI) methods are used, followed by nonvariational one-center restoration of the four-component wave function in the iodine core. The RCC-SD value is Eeff=0.345x1024 Hz/e cm and SODCI study gives Eeff=0.336x1024 Hz/e cm (our final value). The structure of chemical bonding in HI+ is clarified, and a significant deviation of our value from that of Ravaine et al. [Phys. Rev. Lett. 94, 013001 (2005)] is explained

A new measurement of the anomalous magnetic moment (g-2) and electric dipole moment (EDM) of the positive muon is proposed with a novel technique utilizing an ultra-cold muons accelerated to 300 MeV/c and a 66 cm-diameter compact muon storage ring without focusing-electric field. It requires an intense source of muonium to achieve the design intensity of the ultra-cold muon beam. Test experiments at TRIUMF aims to measure the muonium production rate as well as its space-time distribution in the vacuum for the development of the intense muonium source.

A new measurement of the anomalous magnetic moment ( g-2) and electric dipole moment (EDM) of the positive muon is proposed with a novel technique utilizing an ultra-cold muons accelerated to 300 MeV/c and a 66 cm-diameter compact muon storage ring without focusing-electric field. It requires an intense source of muonium to achieve the design intensity of the ultra-cold muon beam. Test experiments at TRIUMF aims to measure the muonium production rate as well as its space-time distribution in the vacuum for the development of the intense muonium source.

Electrical discharge machining (EDM) is an emerging alternative versus some other manufacturing processes of conductive ceramic materials, such as: laser machining, electrochemical machining, abrasive water jet, ultrasonic machining and diamond wheel grinding. Due to its interest in the industrial field, in this work a study of the influence of process conditions on the surface aspect of three conductive ceramic materials: hot-pressed boron carbide (B4C), reaction-bonded silicon carbide (SiSiC) and cobalt-bonded tungsten carbide (WC-Co) is carried out. These materials are to be electrical discharge machined under different machining conditions and in the particular case of finish stages (Ra? 1 ?m). (Author)

Purpose: The purpose of this study is the selection of phase composition of Si3N4 matrix ceramics with the addition of conducting phases so as to make shaping of those materials possible by means of electro discharge machining (EDM). Silicon nitride matrix materials with the addition of oxide phases (Al2O3, MgO, ZrO2) and conducting phases (TiB2, TiN) were sintered by the method of SPS (Spark Plasma Sintering). Additionally the effect of oxide phases on silicon nitride sintering capacity, the...

The present study attempts to make comparative investigation of microhole machining process in EDM for using three different dielectrics such as pure kerosene, pure de-ionized water and boron carbide mixed kerosene and de-ionized water. The two most important process parameters i.e. peak current and pulse-on-time were varied keeping other parameters as constant. The experimental results revealed that B4C mixed dielectrics result in non-uniformly circular microholes compared to pure kerosene and de-ionized water. Moreover, when de-ionized water is used, powder mixed dielectric results in generation of accurate microhole with respect to taperness and circularity.

Full Text Available The effect of process parameters on an EDM namely pulse on time (TON, duty cycle (DC, discharge current (I and gap voltage (V were studied based on Tool Overcut (TOC. Taguchi’s L9 orthogonal array was selected for conducting the experiments. Optimization was carried out using Signal to Noise ratios (SNR and the main effects plot based on SNR. Duty cycle was found to be the most significant parameter that effected TOC followed by discharge current and pulse on time. Gap voltage had the least effect on TOC.

At present we know of three kinds of neutral leptons: the electron neutrino, the muon neutrino, and the tau neutrino. This paper reviews the search for additional neutral leptons. The method and significance of a search depends upon the model used for the neutral lepton being sought. Some models for the properties and decay modes of proposed neutral leptons are described. Past and present searches are reviewed. The limits obtained by some completed searches are given, and the methods of searches in progress are described. Future searches are discussed. 41 references.

Full Text Available The existence of new heavy neutral massive boson Z? is a feature of many extensions of Standard Model models as the two-Higgs-doublet model (2HDM, the Hidden Abelian Higgs Model (HAHM, Left-Right Symmetric Model (LRSM, Sequential Standard Model (SSM and Baryon number minus Lepton number Model (B-L. In the present work we search for two high energy electrons produced from decayingheavy neutral massive boson in the events produced in proton-proton collisions at LHC and can be detected by CMS detector. We used the data which is produced from proton-proton collisions by Monte Carlo events generator for different energies at LHC, then we use the angular distribution, invariant mass, combined transverse momentum and combined rapidity distributions for the two high energy electrons produced from decay channel to detect thesignal. B-L extension of the SM model predicts the existence of aheavy neutral massive boson at high energies. From our results which we had simulated using MC programs forin the B-L extension of standard model, we predict a possible existence of new gaugeat LHC in the mass range 1 TeV to 1.5 TeV via electrons identification of the two high energy electrons by CMS detector.

We present a preliminary analysis of the UA2 data collected during the last Collider run (20 nb-1 integrated luminosity) with particular emphasis on large transverse momentum hadron jets and on electrons having the configuration expected from the decay of electroweak bosons. The data provide very strong evidence of two-jet dominance in events with large transverse energy in the central region. Four electron candidates have been observed with a transverse momentum in excess of 20 GeV/c, which are associated with no other large transverse energy production within the UA2 acceptance. While this result is in all respects consistent with a W -> e? hypothesis, more work is needed to ensure that the background is well understood and to further ascertain electron identification. No electron pair was detected with an invariant mass in excess of 40 GeV/c2. (orig.)

We give a short overview of the DarkLight detector concept which is designed to search for a heavy photon A' with a mass in the range 10 MeV/c^2 < m(A') < 90 MeV/c^2 and which decays to lepton pairs. We describe the intended operating environment, the Jefferson Laboratory free electon laser, and a way to extend DarkLight's reach using A' --> invisible decays.

Working with Kolya Uraltsev was a real `marvel' for me about CP & T violation, QCD & its impact on transitions in heavy flavor hadrons, EDMs etc. etc. The goal was (and still is) to define fundamental parameters dynamics, how to measure them and compare SM forces with New Dynamics using the best theoretical tools. The correlations of them with accurate data were crucial for Kolya. Here is a review of CP asymmetries in $B$ & $D$ mesons and $\\tau$ decays, the impact of perturbative and non-perturbative QCD, about EDMs till 2012 -- and for the future.

A novel miniature diamond grinding tool usable for the precise micro-grinding of miniature parts is presented. A hybrid process that combines 'micro-EDM' with 'precision co-deposition' is proposed. The metal substrate is micro-EDMed to a 50 µm diameter and micro diamonds with 0–2 µm grains are 'electroformed' on the substrate surface, producing a miniature multilayered grinding tool. Nickel and diamond act as binders and cutters, respectively. A partition plate with an array of drilled holes is designed to ensure good convection in the electroforming solution. The dispersion of diamond grains and displacement of nickel ions are noticeably improved. A miniature funnel mould enables the diamond grains to converge towards the cathode to increase their deposition probability on the substrate, thereby improving their distribution on the substrate surface. A micro ZrO2 ceramic ferrule is finely ground by the developed grinding tool and then yields a surface roughness of Ra = 0.085 µm. The proposed approach is applied during the final machining process